Blends of α-olefin/vinylidene aromatic monomer or hindered aliphatic vinylidene monomer interpolymers with polyolefins

ABSTRACT

A fabricated article other than a film comprising a thermoplastic blend prepared from polymeric materials consisting of; (A) from 1 to 99 weight percent of at least one interpolymer made from monomer components comprising (1) from 0.5 to 65 mole percent of (a) at least one aromatic vinylidene monomer, or (b) at least one hindered aliphatic or cycloaliphatic vinylidene monomer, or (c) a combination of at least one aromatic vinylidene monomer and at least one hindered aliphatic or cycloaliphatic vinylidene monomer, and (2) from 99.5 to 35 mole percent of at least one aliphatic α-olefin having from 2 to 20 carbon atoms; and (B) from 99 to 1 weight percent of at least one polymer made from monomer components comprising at least one α-olefin having from 2 to 20 carbon atoms. 
     These articles possess improved properties when compared to the properties of articles derived from the individual polymers comprising the blend. These articles are useful in the preparation of injection molded parts, bitumen and asphalt modification, hot melt and pressure sensitive adhesive systems.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a national application of International ApplicationNo. PCT/US 97/15533 filed on Sep. 4, 1997, claiming priority from U.S.Provisional Application Ser. No. 60/025,431, filed on Sep. 4, 1996, allof which are incorporated herein by reference in their entirety.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

FIELD OF THE INVENTION

The present invention pertains to blends (A) of interpolymers made frommonomer components comprising at least one α-olefin and at least onearomatic vinylidene monomer and/or at least one hindered aliphaticvinylidene monomer and/or at least one cycloaliphatic vinylidene monomerand (B) olefinic polymers.

The generic class of materials covered by α-olefin/hindered vinylidenemonomer substantially random interpolymers and including materials suchas α-olefin/vinyl aromatic monomer interpolymers are known in the artand offer a range of material structures and properties which makes themuseful for varied applications, such as compatibilizers for blends ofpolyethylene and polystyrene as described in U.S. Pat. No. 5,460,818.

One particular aspect described by D'Anniello et al. (Journal of AppliedPolymer Science, Volume 58, pages 1701-1706 (1995)) is that suchinterpolymers can show good elastic properties and energy dissipationcharacteristics. In another aspect, selected interpolymers can findutility in adhesive systems, as illustrated in U.S. Pat. No. 5,244,996,issued to Mitsui Petrochemical Industries Ltd.

Although of utility in their own right, Industry is constantly seekingto improve the applicability of these interpolymers, for example toextend the temperature range of application. Such enhancements may beaccomplished via additives, but it is desirable to develop technologiesto provide improvements in processability or performance without theaddition of additives or further improvements than can be achieved withthe addition of additives.

Park et al., in WO 95/27755 describes a method of increasing thetoughness and solvent resistance of a homopolymer or interpolymer of amonovinylidene aromatic monomer, by blending it with an olefin polymersuch as a polyethylene or ethylene/octene copolymer. However because ofthe incompatability of these two types of resins, there is a requirementfor a compatabilizer which Park teaches can be a pseudo randominterpolymer of an aliphatic α-olefin and a vinylidene aromatic monomer.

Bradfute et al., in WO 95/32095 discloses multilayer films having atleast one layer which is an ethylene/styrene copolymer.

McKay et al., in WO 96/07681 describes a thermoset elastomer comprisinga crosslinked pseudorandom or substantially random interpolymer of atleast one α-olefin, at least one vinylidene aromatic compound, and atleast one diene. The subject invention also provides a thermoplasticvulcanizate comprising the thermoset elastomer as provided in athemoplastic polyolefin matrix.

There is a need to provide materials based on α-olefin/vinylidenearomatic monomer interpolymers with superior performance characteristicsto the unmodified polymers, which will further expand the utility ofthis interesting class of materials. This superior characteristicsinclude, but are not limited to, low temperature toughness, mechanicalstrength and melt processability.

The present invention pertains to a fabricated article other than a filmcomprising a blend of polymeric materials consisting of

(A) from 1 to 99 weight percent of one or more α-olefin/vinylidenemonomer non-crosslinked substantially random interpolymers, wherein thedistribution of the monomers of said interpolymers can be described bythe Bernoulli statistical model or by a first or second order Markovianstatistical model, and each having been made from monomer componentscomprising:

(1) from 0.5 to 65 mole percent of either

(a) at least one vinylidene aromatic monomer, or

(b) at least one hindered aliphatic vinylidene monomer, corresponding tothe formula:

 wherein A¹ is a sterically bulky, aliphatic or cycloaliphaticsubstituent of up to 20 carbons, R¹ is selected from the group ofradicals consisting of hydrogen and alkyl radicals containing from 1 to4 carbon atoms, preferably hydrogen or methyl; each R² is independentlyselected from the group of radicals consisting of hydrogen and alkylradicals containing from 1 to 4 carbon atoms, preferably hydrogen ormethyl; or alternatively R¹ and A¹ together form a ring system or

(c) a combination of at least one vinylidene aromatic monomer and atleast one hindered aliphatic vinylidene monomer; and

(2) from 35 to 99.5 mole percent of at least one aliphatic α-olefinhaving from 2 to 20 carbon atoms; and

(B) from 99 to 1 weight percent of one or more homopolymers orcopolymers of monomer components comprising aliphatic α-olefins havingfrom 2 to 20 carbon atoms, or aliphatic α-olefins having from 2 to 20carbon atoms and containing polar groups.

The present invention also pertains to an expandable compositioncomprising the aforementioned blend and a foaming or expansion agent.

The blends and or foams of the present invention can “comprise”,“consist essentially of” or “consist of” any two or more of suchpolymers or interpolymers enumerated herein.

These blends provide an improvement in one or more of the polymerproperties such as, but not limited to, mechanical properties, lowtemperature performance, relaxation/damping behavior and melt flowproperties as compared to a like property of either of the individualpolymers of said blend.

The term “interpolymer” is used herein to indicate a polymer wherein atleast two different monomers are polymerized to make the interpolymer.

The term “copolymer” as employed herein means a polymer wherein at leasttwo different monomers are polymerized to form the copolymer.

The term “mer(s)” means the polymerized unit of the polymer derived fromthe indicated monomer(s).

The term “monomer residue” or “polymer units derived from” means thatportion of the polymerizable monomer molecule which resides in thepolymer chain as a result of being polymerized with anotherpolymerizable molecule to make the polymer chain.

The term “substantially random” in the substantially random interpolymerresulting from polymerizing one or more α-olefin monomers and one ormore vinylidene aromatic monomers or hindered aliphatic orcycloaliphatic vinylidene monomers, and optionally, with otherpolymerizable ethylenically unsaturated monomer(s) as used herein meansthat the distribution of the monomers of said interpolymer can bedescribed by the Bernoulli statistical model or by a first or secondorder Markovian statistical model, as described by J. C. Randall inPOLYMER SEQUENCE DETERMINATION, Carbon-13 NMR Method, Academic Press NewYork, 1977, pp. 71-78. Preferably, the substantially random interpolymerresulting from polymerizing one or more a-olefin monomers and one ormore vinylidene aromatic monomer, and optionally, with otherpolymerizable ethylenically unsaturated monomer(s) does not contain morethan 15 percent of the total amount of vinylidene aromatic monomer inblocks of vinylidene aromatic monomer of more than 3 units. Morepreferably, the interpolymer was not characterized by a high degree ofeither isotacticity or syndiotacticity. This means that in the carbon⁻¹³NMR spectrum of the substantially random interpolymer the peak areascorresponding to the main chain methylene and methine carbonsrepresenting either meso diad sequences or racemic diad sequences shouldnot exceed 75 percent of the total peak area of the main chain methyleneand methine carbons.

Any numerical values recited herein include all values from the lowervalue to the upper value in increments of one unit provided that thereis a separation of at least 2 units between any lower value and anyhigher value. As an example, if it is stated that the amount of acomponent or a value of a process variable such as, for example,temperature, pressure, time is, for example, from 1 to 90, preferablyfrom 20 to 80, more preferably from 30 to 70, it is intended that valuessuch as 15 to 85, 22 to 68, 43 to 51, 30 to 32 are expressly enumeratedin this specification. For values which are less than one, one unit isconsidered to be 0.0001, 0.001, 0.01 or 0.1 as appropriate. These areonly examples of what is specifically intended and all possiblecombinations of numerical values between the lowest value and thehighest value enumerated are to be considered to be expressly stated inthis application in a similar manner.

At The interpolymers suitable as component (A) for the blends comprisingthe present invention include substantially random interpolymers eachhaving been made from monomer components comprising one or more α-olefinmonomers with one or more vinylidene aromatic monomers and/or one ormore hindered aliphatic or cycloaliphatic vinylidene monomers, andoptionally with other polymerizable ethylenically unsaturatedmonomer(s). The interpolymers are also prepared by polymerizing one ormore α-olefin monomers with one or more vinylidene aromatic monomersand/or one or more hindered aliphatic or cycloaliphatic vinylidenemonomers, and optionally with other polymerizable ethylenicallyunsaturated monomer(s).

Suitable α-olefin monomers include for example, α-olefin monomerscontaining from 2 to 20, preferably from 2 to 12, more preferably from 2to 8 carbon atoms. Preferred such monomers include ethylene, propylene,butene-1, 4-methyl-1-pentene, hexene-1 and octene-1. Most preferred areethylene or a combination of ethylene with C₃₋₈ α-olefins. Theseα-olefins do not contain an aromatic moiety.

Other optional polymerizable ethylenically unsaturated monomer(s)include strained ring olefins such as norbornene and C₁₋₁₀ alkyl orC₆₋₁₀ aryl substituted norbornenes, with an exemplary interpolymer beingethylene/styrene/norbornene.

Suitable vinylidene aromatic monomers which can be employed to preparethe interpolymers employed in the blends include, for example, thoserepresented by the following formula:

wherein R¹ is selected from the group of radicals consisting of hydrogenand alkyl radicals containing from 1 to 4 carbon atoms, preferablyhydrogen or methyl; each R² is independently selected from the group ofradicals consisting of hydrogen and alkyl radicals is containing from 1to 4 carbon atoms, preferably hydrogen or methyl; Ar is a phenyl groupor a phenyl group substituted with from 1 to 5 substituents selectedfrom the group consisting of halo, C₁₋₄-alkyl, and C₁₋₄-haloalkyl; and nhas a value from zero to 4, preferably from zero to 2, most preferablyzero. Exemplary monovinylidene aromatic monomers include styrene, vinyltoluene, .αa-methylstyrene, t-butyl styrene, chlorostyrene, includingall isomers of these compounds. Particularly suitable such monomersinclude styrene and lower alkyl- or halogen-substituted derivativesthereof. Preferred monomers include styrene, a-methyl styrene, the loweralkyl-(C₁-C₄) or phenyl-ring substituted derivatives of styrene, such asfor example, ortho-, meta-, and para-methylstyrene, the ring halogenatedstyrenes, para-vinyl toluene or mixtures thereof. A more preferredaromatic monovinylidene monomer is styrene.

By the term “hindered aliphatic or cycloaliphatic vinylidene compounds”,it is meant addition polymerizable vinylidene monomers corresponding tothe formula:

wherein A¹ is a sterically bulky, aliphatic or cycloaliphaticsubstituent of up to 20 carbons, R¹ is selected from the group ofradicals consisting of hydrogen and alkyl radicals containing from 1 to4 carbon atoms, preferably hydrogen or methyl; each R² is independentlyselected from the group of radicals consisting of hydrogen and alkylradicals containing from 1 to 4 carbon atoms, preferably hydrogen ormethyl; or alternatively R¹ and A¹ together form a ring system. By theterm “sterically bulky” is meant that the monomer bearing thissubstituent is normally incapable of addition polymerization by standardZiegler-Natta polymerization catalysts at a rate comparable withethylene polymerizations. α-Olefin monomers containing from 2 to 20carbon atoms and having a linear aliphatic structure such as propylene,butene-1, hexene-1 and octene-1 are not considered as hindered aliphaticmonomers. Preferred hindered aliphatic or cycloaliphatic vinylidenecompounds are monomers in which one of the carbon atoms bearingethylenic unsaturation is tertiary or quaternary substituted. Examplesof such substituents include cyclic aliphatic groups such as cyclohexyl,cyclohexenyl, cyclooctenyl, or ring alkyl or aryl substitutedderivatives thereof, tert-butyl, and norbornyl. Most preferred hinderedaliphatic or cycloaliphatic vinylidene compounds are the variousisomeric vinyl-ring substituted derivatives of cyclohexene andsubstituted cyclohexenes, and 5-ethylidene-2-norbornene. Especiallysuitable are 1-, 3-, and 4-vinylcyclohexene.

The interpolymers of one or more α-olefins and one or moremonovinylidene aromatic monomers and/or one or more hindered aliphaticor cycloaliphatic vinylidene monomers employed in the present inventionare substantially random polymers. These interpolymers usually containfrom 0.5 to 65, preferably from 1 to 55, more preferably from 2 to 50mole percent of at least one vinylidene aromatic monomer and/or hinderedaliphatic or cycloaliphatic vinylidene monomer and from 35 to 99.5,preferably from 45 to 99, more preferably from 50 to 98 mole percent ofat least one aliphatic α-olefin having from 2 to 20 carbon atoms.

Other optional polymerizable ethylenically unsaturated monomer(s)include strained ring olefins such as norbornene and C₁₋₁₀ alkyl orC₆₋₁₀ aryl substituted norbornenes, with an exemplary interpolymer beingethylene/styrene/norbornene.

The number average molecular weight (Mn) of the polymers andinterpolymers is usually greater than 5,000, preferably from 20,000 to1,000,000, more preferably from 50,000 to 500,000.

Polymerizations and unreacted monomer removal at temperatures above theautopolymerization temperature of the respective monomers may result information of some amounts of homopolymer polymerization productsresulting from free radical polymerization. For example, while preparingthe substantially random interpolymer, an amount of atactic vinylidenearomatic homopolymer may be formed due to homopolymerization of thevinylidene aromatic monomer at elevated temperatures. The presence ofvinylidene aromatic homopolymer is in general not detrimental for thepurposes of the present invention and can be tolerated. The vinylidenearomatic homopolymer may be separated from the interpolymer, if desired,by extraction techniques such as selective precipitation from solutionwith a non solvent for either the interpolymer or the vinylidenearomatic homopolymer. For the purpose of the present invention it ispreferred that no more than 20 weight percent, preferably less than 15weight percent based on the total weight of the interpolymers ofvinylidene aromatic homopolymer is present.

The substantially random interpolymers may be modified by typicalgrafting, hydrogenation, functionalizing, or other reactions well knownto those skilled in the art. The polymers may be readily sulfonated orchlorinated to provide functionalized derivatives according toestablished techniques.

The substantially random interpolymers can be produced by polymerizationor copolymerization of the appropriate monomers in the presence of ametallocene catalyst and a co-catalyst as described in EP-A-0,416,815 byJames C. Stevens et al., and U.S. Pat. No. 5,703,187 by Francis J.Timmers. Preferred operating conditions for such polymerizationreactions are pressures from atmospheric up to 3,000 atmospheres andtemperatures from −30° C. to 200° C.

Examples of suitable catalysts and methods for preparing thesubstantially random interpolymers are disclosed in EP-A-514,828; aswell as U.S. Pat. Nos: 5,055,438; 5,057,475; 5,096,867; 5,064,802;5,132,380; 5,189,192; 5,321,106; 5,347,024; 5,350,723; 5,374,696;5,399,635; 5,470,993; 5,703,187; and 5,721,185.

The substantially random α-olefin/vinylidene aromatic interpolymers canalso be prepared by the methods described by John G. Bradfute et al. (W.R. Grace & Co.) in WO 95/32095; by R. B. Pannell (Exxon ChemicalPatents, Inc.) in WO 94/00500; and in Plastics Technology, p. 25(September 1992).

Also suitable are the substantially random interpolymers which compriseat least one α-olefin/vinyl aromatic/vinyl aromatic/α-olefin tetraddisclosed in Wo 98/09999 by Francis J. Timmers et al. Theseinterpolymers contain additional signals with intensities greater thanthree times the peak to peak noise. These signals appear in the chemicalshift range 43.70-44.25 ppm and 38.0-38.5 ppm. Specifically, major peaksare observed at 44.1, 43.9 and 38.2 ppm. A proton test NMR experimentindicates that the signals in the chemical shift region 43.70-44.25 ppmare methine carbons and the signals in the region 38.0-38.5 ppm aremethylene carbons.

In order to determine the carbon⁻¹³ NMR chemical shifts of theinterpolymers described, the following procedures and conditions areemployed. A five to ten weight percent polymer solution is prepared in amixture consisting of 50 volume percent 1,1,2,2-tetrachloroethane-d₂ and50 volume percent 0.10 molar chromium tris(acetylacetonate) in1,2,4-trichlorobenzene. NMR spectra are acquired at 130° C. using aninverse gated decoupling sequence, a 90° pulse width and a pulse delayof five seconds or more. The spectra are referenced to the isolatedmethylene signal of the polymer assigned at 30.000 ppm.

It is believed that these new signals are due to sequences involving twohead-to-tail vinyl aromatic monomer preceded and followed by at leastone α-olefin insertion, e.g. an ethylene/styrene/styrene/ethylene tetradwherein the styrene monomer insertions of said tetrads occur exclusivelyin a 1,2 (head to tail) manner. It is understood by one skilled in theart that for such tetrads involving a vinyl aromatic monomer other thanstyrene and an α-olefin other than ethylene that the ethylene/vinylaromatic monomer/vinyl aromatic monomer/ethylene tetrad will give riseto similar carbon⁻¹³ NMR peaks but with slightly different chemicalshifts.

These interpolymers are prepared by conducting the polymerization attemperatures of from −30° C. to 250° C. in the presence of suchcatalysts as those represented by the formula

wherein: each Cp is independently, each occurrence, a substitutedcyclopentadienyl group π-bound to M; E is C or Si; M is a group IVmetal, preferably Zr or Hf, most preferably Zr; each R is independently,each occurrence, H, hydrocarbyl, silahydrocarbyl, or hydrocarbylsilyl,containing up to 30 preferably from 1 to 20 more preferably from 1 to 10carbon or silicon atoms; each R′ is independently, each occurrence, H,halo, hydrocarbyl, hyrocarbyloxy, silahydrocarbyl, hydrocarbylsilylcontaining up to 30 preferably from 1 to 20 more preferably from 1 to 10carbon or silicon atoms or two R′ groups together can be a C₁₋₁₀hydrocarbyl substituted 1,3-butadiene; m is 1 or 2; and optionally, butpreferably in the presence of an activating cocatalyst. Particularly,suitable substituted cyclopentadienyl groups include those illustratedby the formula:

wherein each R is independently, each occurrence, H, hydrocarbyl,silahydrocarbyl, or hydrocarbylsilyl, containing up to 30 preferablyfrom 1 to 20 more preferably from 1 to 10 carbon or silicon atoms or twoR groups together form a divalent derivative of such group. Preferably,R independently each occurrence is (including where appropriate allisomers) hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, benzyl,phenyl or silyl or (where appropriate) two such R groups are linkedtogether forming a fused ring system such as indenyl, fluorenyl,tetrahydroindenyl, tetrahydrofluorenyl, or octahydrofluorenyl.

Particularly preferred catalysts include, for example,racemic-(dimethylsilanediyl)-bis-(2-methyl-4-phenylindenyl))zirconiumdichloride,racemic-(dimethylsilanediyl)-bis-(2-methyl-4-phenylindenyl))zirconium1,4-diphenyl-1,3-butadiene,racemic-(dimethylsilanediyl)-bis-(2-methyl-4-phenylindenyl))zirconiumdi-C₁₋₄ alkyl,racemic-(dimethylsilanediyl)-bis-(2-methyl-4-phenylindenyl)) zirconiumdi-C₁₋₄ alkoxide, or any combination thereof.

Further preparative methods for the interpolymer component (A) of thepresent invention have been described in the literature. Longo andGrassi (Makromol. Chem., Volume 191, pages 2387 to 2396 [1990]) andD'Anniello et al. (Journal of Applied Polymer Science, Volume 58, pages1701-1706 [1995]) reported the use of a catalytic system based onmethylalumoxane (MAO) and cyclopentadienyltitanium trichloride (CpTiCl₃)to prepare an ethylene-styrene copolymer. Xu and Lin (Polymer Preprints,Am.Chem.Soc.,Div.Polym.Chem.) Volume 35, pages 686, 687 [1994]) havereported copolymerization using a MgCl₂/TiCl₄/NdCl₃/Al(iBu)₃ catalyst togive random copolymers of styrene and propylene. Lu et al (Journal ofApplied Polymer Science, Volume 53, pages 1453 to 1460 [1994]) havedescribed the copolymerization of ethylene and styrene using aTiCl₄/NdCl₃/MgCl₂/Al(Et)₃ catalyst. Sernetz and Mulhaupt, (Macromol.Chem. Phys., v. 197, pp 1071-1083, 1997) have described the influence ofpolymerization conditions on the copolymerization of styrene withethylene using Me₂Si(Me₄Cp) (N-tert-butyl)TiCl₂/methylaluminoxaneZiegler-Natta catalysts. The manufacture of α-olefin/vinyl aromaticmonomer interpolymers such as propylene/styrene and butene/styrene aredescribed in U.S. Pat. No. 5,244,996, issued to Mitsui PetrochemicalIndustries Ltd.

Olefinic polymers suitable for use as component (B) in the blendsaccording to the present invention are aliphatic α-olefin homopolymersor interpolymers, or interpolymers of one or more aliphatic α-olefinsand one or more non-aromatic monomers interpolymerizable therewith suchas C₂-C₂₀ α-olefins or those aliphatic α-olefins having from 2 to 20carbon atoms and containing polar groups. Suitable aliphatic α-olefinmonomers which introduce polar groups into the polymer include, forexample, ethylenically unsaturated nitrites such as acrylonitrile,methacrylonitrile, ethacrylonitrile, etc.; ethylenically unsaturatedanhydrides such as maleic anhydride; ethylenically unsaturated amidessuch as acrylamide, methacrylamide etc.; ethylenically unsaturatedcarboxylic acids (both mono- and difunctional) such as acrylic acid andmethacrylic acid, etc.; esters (especially lower, e.g. C₁-C₆, alkylesters) of ethylenically unsaturated carboxylic acids such as methylmethacrylate, ethyl acrylate, hydroxyethylacrylate, n-butyl acrylate ormethacrylate, 2-ethyl-hexylacrylate etc.; ethylenically unsaturateddicarboxylic acid imides such as N-alkyl or N-aryl maleimides such asN-phenyl maleimide. Preferably such monomers containing polar groups areacrylic acid, vinyl acetate, maleic anhydride and acrylonitrile. Halogengroups which can be included in the polymers from aliphatic α-olefinmonomers include fluorine, chlorine and bromine; preferably suchpolymers are chlorinated polyethylenes (CPEs). Preferred olefinicpolymers for use in the present invention are homopolymers orinterpolymers of an aliphatic, including cycloaliphatic, α-olefin havingfrom 2 to 18 carbon atoms. Suitable examples are homopolymers ofethylene or propylene, and interpolymers of two or more α-olefinmonomers. Other preferred olefinic polymers are interpolymers ofethylene and one or more other α-olefins having from 3 to 8 carbonatoms. Preferred comonomers include 1-butene, 4-methyl-1-pentene,1-hexene, and 1-octene. The olefinic polymer blend component (B) mayalso contain, in addition to the α-olefin, one or more non-aromaticmonomers interpolymerizable therewith. Such additionalinterpolymerizable monomers include, for example, C₄-C₂₀ dienes,preferably, butadiene or 5 ethylidene-2-norbornene. The olefinicpolymers can be further characterized by their degree of long or shortchain branching and the distribution thereof.

One class of olefinic polymers is generally produced by a high pressurepolymerization process using a free radical initiator resulting in thetraditional long chain branched low density polyethylene (LDPE). LDPEemployed in the present composition usually has a density of less than0.94 g/cc (ASTM D 792) and a melt index of from 0.01 to 100, andpreferably from 0.1 to 50 grams per 10 minutes (as determined by ASTMTest Method D 1238, condition I).

Another class is the linear olefin polymers which have an absence oflong chain branching, as the traditional linear low density polyethylenepolymers (heterogeneous LLDPE) or linear high density polyethylenepolymers (HDPE) made using Ziegler polymerization processes (forexample, U.S. Pat. No. 4,076,698 (Anderson et al.), sometimes calledheterogeneous polymers.

HDPE consists mainly of long linear polyethylene chains. The HDPEemployed in the present composition usually has a density of at least0.94 grams per cubic centimeter (g/cc) as determined by ASTM Test MethodD 1505, and a melt index (ASTM-1238, condition I) in the range of from0.01 to 100, and preferably from 0.1 to 50 grams per 10 minutes.

The heterogeneous LLDPE employed in the present composition generallyhas a density of from 0.85 to 0.94 g/cc (ASTM D 792), and a melt index(ASTM-1238, condition I) in the range of from 0.01 to 100, andpreferably from 0.1 to 50 grams per 10 minutes. Preferably the LLDPE isan interpolymer of ethylene and one or more other α-olefins having from3 to 18 carbon atoms, more preferably from 3-8 carbon atoms. Preferredcomonomers include 1-butene, 4-methyl-1-pentene, 1-hexene, and 1-octene.

A further class is that of the uniformly branched or homogeneouspolymers (homogeneous LLDPE). The homogeneous polymers contain no longchain branches and have only branches derived from the monomers (ifhaving more than two carbon atoms). Homogeneous polymers include thosemade as described in U.S. Pat. No. 3,645,992 (Elston), and those madeusing so-called single site catalysts in a batch reactor havingrelatively high olefin concentrations (as described in U.S. Pat. Nos.5,026,798 and 5,055,438 (Canich). The uniformly branched/homogeneouspolymers are those polymers in which the comonomer is randomlydistributed within a given interpolymer molecule and wherein theinterpolymer molecules have a similar ethylene/comonomer ratio withinthat interpolymer.

The homogeneous LLDPE employed in the present composition generally hasa density of from 0.85 to 0.94 g/cc (ASTM D 792), and a melt index(ASTM-1238, condition I) in the range of from 0.01 to 100, andpreferably from 0.1 to 50 grams per 10 minutes. Preferably the LLDPE isan interpolymer of ethylene and one or more other α-olefins having from3 to 18 carbon atoms, more preferably from 3-8 carbon atoms. Preferredcomonomers include 1-butene, 4-methyl-1-pentene, 1-hexene, and 1-octene.

Further, there is the class of substantially linear olefin polymers(SLOP) that may advantageously be used in component (B) of the blends ofthe present invention. These polymers have a processability similar toLDPE, but the strength and toughness of LLDPE. Similar to thetraditional homogeneous polymers, the substantially linearethylene/α-olefin interpolymers have only a single melting peak, asopposed to traditional Ziegler polymerized heterogeneous linearethylene/α-olefin interpolymers which have two or more melting peaks(determined using differential scanning calorimetry). Substantiallylinear olefin polymers are disclosed in U.S. Pat. Nos. 5,272,236 and5,278,272.

The density of the SLOP as measured in accordance with ASTM D-792 isgenerally from 0.85 g/cc to 0.97 g/cc, preferably from 0.85 g/cc to0.955 g/cc, and especially from 0.85 g/cc to 0.92 g/cc.

The melt index, according to ASTM D-1238, Condition 190° C./2.16 kg(also known as I₂), of the SLOP is generally from 0.01 g/10 min. to 1000g/10 min., preferably from 0.01 g/10 min. to 100 g/10 min., andespecially from 0.01 g/10 min. to 10 g/10 min.

Also, included are the ultra low molecular weight ethylene polymers andethyl-ene/α-olefin interpolymers described in the provisional patentapplication (application Ser. No. 60/010,403) entitled Ultra-LowMolecular Weight Polymers, filed provisionally on Jan. 22, 1996, in thenames of M. L. Finlayson, C. C. Garrison, R. E. Guerra, M. J. Guest, B.W. S. Kolthammer, D. R. Parikh, and S. M. Ueligger. Theseethylene/α-olefin interpolymers have I₂ melt indices greater than 1,000,or a number average molecular weight (Mn) less than 11,000.

The SLOP can be a homopolymer of C₂-C₂₀ olefins, such as ethylene,propylene, 4-methyl-1-pentene, etc., or it can be an interpolymer ofethylene with at least one C₃-C₂₀ α-olefin and/or C₂-C₂₀ acetylenicallyunsaturated monomer and/or C₄-C₁₈ diolefin. SLOP can also be aninterpolymer of ethylene with at least one of the above C₃-C₂₀α-olefins, diolefins and/or acetylenically unsaturated monomers incombination with other unsaturated monomers.

Especially preferred olefin polymers suitable for use as component (B)comprise LDPE, HDPE, heterogeneous and homogeneous LLDPE, SLOP,polypropylene (PP), especially isotactic polypropylene and rubbertoughened polypropylenes, or ethylene-propylene interpolymers (EP), orchlorinated polyolefins (CPE), or ethylene-vinyl acetate copolymers, orethylene-acrylic acid copolymers, or any combination thereof.

The blends of the present invention usually comprise from 1 to 99,preferably from 5 to 95 and more preferably from 10 to 90 percent byweight of the interpolymers containing at least one is aromaticvinylidene monomer residue or hindered aliphatic or cycloaliphaticvinylidene monomer residue or any combination thereof (component (A))and from 1 to 99, preferably from 5 to 95, more preferably from 10 to 90percent by weight of the polymers which do not contain any aromaticvinylidene monomer residue or hindered aliphatic or cycloaliphaticvinylidene monomer residue (component (B)). The percentages are based onthe total amount of the polymers constituting the blends.

The blends of the present invention may be prepared by any suitablemeans known in the art such as, but not limited to, dry blending in apelletized form in the desired proportions followed by melt blending ina screw extruder, or Banbury mixer. The dry blended pellets may bedirectly melt processed into a final solid state article by for exampleinjection molding. Alternatively, the blends may be made by directpolymerization, without isolation of the blend components, using forexample one or more catalysts in one reactor or two or-more reactors inseries or parallel.

The foam structure of the present invention may take any physicalconfiguration known in the art, such as sheet, plank, or bun stock.Other useful forms are expandable or foamable particles, moldable foamparticles, or beads, and articles formed by expansion and/or coalescingand welding of those particles.

Excellent teachings to processes for making ethylenic polymer foamstructures and processing them are seen in C. P. Park, “PolyolefinFoam”, Chapter 9, Handbook of Polymer Foams and Technology, edited by D.Klempner and K. C. Frisch, Hanser Publishers, Munich, Vienna, New York,Barcelona (1991).

The present foam structure may be made by a conventional extrusionfoaming process. The structure is generally prepared by heating anethylenic polymer material to form a plasticized or melt polymermaterial, incorporating therein a blowing agent to form a foamable gel,and extruding the gel through a die to form the foam product. Prior tomixing with the blowing agent, the polymer material is heated to atemperature at or above its glass transition temperature or meltingpoint. The blowing agent may be incorporated or mixed into the meltpolymer material by any means known in the art such as with an extruder,mixer, or blender. The blowing agent is mixed with the melt polymermaterial at an elevated pressure sufficient to prevent substantialexpansion of the melt polymer material and to generally disperse theblowing agent homogeneously therein. Optionally, a nucleator may beblended in the polymer melt or dry blended with the polymer materialprior to plasticizing or melting. The foamable gel is typically cooledto a lower temperature to optimize physical characteristics of the foamstructure. The gel is then extruded or conveyed through a die of desiredshape to a zone of reduced or lower pressure to form the foam structure.The zone of lower pressure is at a pressure lower Ethan that in whichthe foamable gel is maintained prior to extrusion through the die. Thelower pressure may be superatmospheric or subatmospheric (vacuum), butis preferably at an atmospheric level.

The present foam structure may be formed in a coalesced strand form byextrusion of the ethylenic polymer material through a multi-orifice die.The orifices are arranged so that contact between adjacent streams ofthe molten extrudate occurs during the foaming process and thecontacting surfaces adhere to one another with sufficient adhesion toresult in a unitary foam structure. The streams of molten extrudateexiting the die take the form of strands or profiles, which desirablyfoam, coalesce, and adhere to one another to form a unitary structure.Desirably, the coalesced individual strands or profiles should remainadhered in a unitary structure to prevent strand delamination understresses encountered in preparing, shaping, and using the foam.Apparatuses and methods for producing foam structures in coalescedstrand form are seen in U.S. Pat. Nos. 3,573,152 and 4,824,720.

The present foam structure may also be formed by an accumulatingextrusion process as seen in U.S. Pat. No. 4,323,528. In this process,low density foam structures having large lateral cross-sectional areasare prepared by: 1) forming under pressure a gel of the ethylenicpolymer material and a blowing agent at a temperature at which theviscosity of the gel is sufficient to retain the blowing agent when thegel is allowed to expand; 2) extruding the gel into a holding zonemaintained at a temperature and pressure which does not allow the gel tofoam, the holding zone having an outlet die defining an orifice openinginto a zone of lower pressure at which the gel foams, and an openablegate closing the die orifice; 3) periodically opening the gate; 4)substantially concurrently applying mechanical pressure by a movable ramon the gel to eject it from the holding zone through the die orificeinto the zone of lower pressure, at a rate greater than that at whichsubstantial foaming in the die orifice occurs and less than that atwhich substantial irregularities in cross-sectional area or shapeoccurs; and 5) permitting the ejected gel to expand unrestrained in atleast one dimension to produce the foam structure.

The present foam structure may also be formed into non-crosslinked foambeads suitable for molding into articles. To make the foam beads,discrete resin particles such as granulated resin pellets-are: suspendedin a liquid medium in which they are substantially insoluble such aswater; impregnated with a blowing agent by introducing the blowing agentinto the liquid medium at an elevated pressure and temperature in anautoclave or other pressure vessel; and rapidly discharged into theatmosphere or a region of reduced pressure to expand to form the foambeads. This process is well taught in U.S. Pat. Nos. 4,379,859 and4,464,484.

In a derivative of the above process, styrene monomer may be impregnatedinto the suspended pellets prior to impregnation with blowing agent toform a graft interpolymer with the ethylenic polymer material. Thepolyethylene/polystyrene interpolymer beads are cooled and dischargedfrom the vessel substantially unexpanded. The beads are then expandedand molded by the conventional expanded polystyrene bead moldingprocess. The process of making the polyethylene/polystyrene interpolymerbeads is described in U.S. Pat. No. 4,168,353.

The foam beads may then be molded by any means known in the art, such ascharging the foam beads to the mold, compressing the mold to compressthe beads, and heating the beads such as with steam to effect coalescingand welding of the beads to form the article. Optionally, the beads maybe impregnated with air or other blowing agent at an elevated pressureand temperature prior to charging to the mold. Further, the beads may beheated prior to charging. The foam beads may then be molded to blocks orshaped articles by a suitable molding method known in the art. (Some ofthe methods are taught in U.S. Pat. Nos. 3,504,068 and 3,953,558.)Excellent teachings of the above processes and molding methods are seenin C. P. Park, supra, p. 191, pp. 197-198, and pp. 227-229.

Blowing agents useful in making the present foam structure includeinorganic agents, organic blowing agents and chemical blowing agents.Suitable inorganic blowing agents include carbon dioxide, nitrogen,argon, water, air, nitrogen, and helium. Organic blowing agents includealiphatic hydrocarbons having 1-6 carbon atoms, aliphatic alcoholshaving 1-3 carbon atoms, and fully and partially halogenated aliphatichydrocarbons having 1-4 carbon atoms. Aliphatic hydrocarbons includemethane, ethane, propane, n-butane, isobutane, n-pentane, isopentane, orneopentane. Aliphatic alcohols include methanol, ethanol, n-propanol,and isopropanol. Fully and partially halogenated aliphatic hydrocarbonsinclude fluorocarbons, chlorocarbons, and chlorofluorocarbons. Examplesof fluorocarbons include methyl fluoride, perfluoromethane, ethylfluoride, 1,1-difluoroethane (HFC-152a), 1,1,1-trifluoroethane(HFC-143a), 1,1,1,2-tetrafluoro-ethane (HFC-134a), pentafluoroethane,difluoromethane, perfluoroethane, 2,2-difluoropropane,1,1,1-trifluoropropane, perfluoropropane, dichloropropane,difluoropropane, perfluorobutane, perfluorocyclobutane. Partiallyhalogenated chlorocarbons and chlorofluorocarbons for use in thisinvention include methyl chloride, methylene chloride, ethyl chloride,1,1,1-trichloroethane, 1,1-dichloro-1-fluoroethane (HCFC-141b),1-chloro-1,1 difluoroethane (HCFC-142b),1,1-dichloro-2,2,2-trifluoroethane (HCFC-123) and1-chloro-1,2,2,2-tetrafluoroethane(HCFC-124). Fully halogenatedchlorofluorocarbons include trichloromonofluoromethane (CFC-11),dichlorodifluoromethane (CFC-12), trichlorotrifluoroethane (CFC-113),1,1,1-trifluoroethane, pentafluoroethane, dichlorotetrafluoroethane(CFC-114), chloroheptafluoropropane, and dichlorohexafluoropropane.Chemical blowing agents include azodicarbonamide,azodiisobutyro-nitrile, benezenesulfonhydrazide, 4,4-oxybenzenesulfonyl-semicarbazide, p-toluene sulfonyl semi-carbazide, bariumazodicarboxylate, N,N′-dimethyl-N,N′-dinitrosoterephthalamide, andtrihydrazino triazine. Preferred blowing agents include isobutane,HFC-152a, and mixtures of the foregoing.

The amount of blowing agents incorporated into the polymer melt materialto make a foam-forming polymer gel is from 0.2 to 5.0, preferably from0.5 to 3.0, and most preferably from 1.0 to 2.50 gram moles per kilogramof polymer.

Foams may be perforated to enhance or accelerate permeation of blowingagent from the foam and air into the foam. The foams may be perforatedto form channels which extend entirely through the foam from one surfaceto another or partially through the foam. The channels may be spaced upto 2.5 centimeters apart and preferably up to 1.3 centimeters apart. Thechannels are present over substantially an entire surface of the foamand preferably are uniformly dispersed over the surface. The foams mayemploy a stability control agent of the type described above incombination with perforation to allow accelerated permeation or releaseof blowing agent while maintaining a dimensionally stable foam.Excellent teachings to perforation of foam are seen in U.S. Pat. No.Nos. 5,424,016 and 5,585,058.

Various additives may be incorporated in the present foam structure suchas stability control agents, nucleating agents, inorganic fillers,pigments, antioxidants, acid scavengers, ultraviolet absorbers, flameretardants, processing aids, or extrusion aids.

A stability control agent may be added to the present foam to enhancedimensional stability. Preferred agents include amides and esters ofC₁₀₋₂₄ fatty acids. Such agents are seen in U.S. Pat Nos. 3,644,230 and4,214,054. Most preferred agents include stearyl stearamide, glycerolmonostearate, glycerol monobehenate, and sorbitol monostearate.Typically, such stability control agents are employed in an amountranging from 0.1 to 10 parts per hundred parts of the polymer.

The present foam structure exhibits excellent dimensional stability.Preferred foams recover 80 or more percent of initial volume within amonth with initial volume being measured within 30 seconds after foamexpansion. Volume is measured by a suitable method such as cubicdisplacement of water.

In addition, a nucleating agent may be added in order to control thesize of foam cells. Preferred nucleating agents include inorganicsubstances such as calcium carbonate, talc, clay, titanium oxide,silica, barium sulfate, diatomaceous earth, mixtures of citric acid andsodium bicarbonate. The amount of nucleating agent employed may rangefrom 0.01 to 5 parts by weight per hundred parts by weight of a polymerresin.

The foam structure is substantially noncross-linked or uncross-linked.The alkenyl aromatic polymer material comprising the foam structure issubstantially free of cross-linking. The foam structure contains no morethan 5 percent gel per ASTM D-2765-84 Method A. A slight degree ofcross-linking, which occurs naturally without the use of cross-linkingagents or radiation, is permissible.

The foam structure has density of less than 250, more preferably lessthan 100 and most preferably from 10 to 70 kilograms per cubic meter.The foam has an average cell size of from 0.05 to 5.0, more preferablyfrom 0.2 to 2.0, and most preferably 0.3 to 1.8 millimeters according toASTM D3576.

The foam structure may take any physical configuration known in the art,such as extruded sheet, rod, plank, and profiles. The foam structure mayalso be formed by molding of expandable beads into any of the foregoingconfigurations or any other configuration.

The foam structure may be closed-celled or open-celled. A closed cellfoam contains 80 percent or more closed cells or less than 20 percentopen cells according to ASTM D2856-A.

Additives such as antioxidants (e.g., hindered phenols such as, forexample, Irganox® 1010, a registered trademark of CIBA-GEIGY),phosphites (e.g., Irgafos® 168, a registered trademark of CIBA-GEIGY),U. V. stabilizers, cling additives (e.g., polyisobutylene), antiblockadditives, colorants, pigments, fillers, can also be included in theinterpolymers employed in the blends of and/or employed in the presentinvention, to the extent that they do not interfere with the enhancedproperties discovered by Applicants.

The additives are employed in functionally equivalent amounts known tothose skilled in the art. For example, the amount of antioxidantemployed is that amount which prevents the polymer or polymer blend fromundergoing oxidation at the temperatures and 35 environment employedduring storage and ultimate use of the polymers. Such amount ofantioxidants is usually in the range of from 0.01 to 10, preferably from0.05 to 5, more preferably from 0.1 to 2 percent by weight based uponthe weight of the polymer or polymer blend. Similarly, the amounts ofany of the other enumerated additives are the functionally equivalentamounts such as the amount to render the polymer or polymer blendantiblocking, to produce the desired amount of filler loading to producethe desired result, to provide the desired color from the colorant orpigment. Such additives can suitably be employed in the range of from0.05 to 50, preferably from 0.1 to 35, more preferably from 0.2 to 20percent by weight based upon the weight of the polymer or polymer blend.However, in the instance of fillers, they could be employed in amountsup to 90 percent by weight based on the weight of the polymer or polymerblend.

The blends of the present invention, in addition to the production offoams, can be utilized to produce a wide range of fabricated articlessuch as, for example, calendered, cast and blown sheets and films andinjection molded parts. The blends further find utilization inapplications such as modifiers for bitumen and asphalt compositions andas components for hot melt and pressure sensitive adhesive systems.

The following examples are illustrative of the invention.

EXAMPLES 1-22 Interpolymer Preparations and Characteristics

Preparation of Interpolymers (A), (C), (G), (H) and (I)

Polymer is prepared in a 400 gallon (1.514 m³) agitated semi-continuousbatch reactor. The reaction mixture consisted of approximately 250gallons (0.95 m³) of a solvent comprising a mixture of cyclohexane (85wt%) & isopentane (15wt %), and styrene. Prior to addition, solvent,styrene and ethylene are purified to remove water and oxygen. Theinhibitor in the styrene is also removed. Inerts are removed by purgingthe vessel with ethylene. The vessel is then pressure controlled to aset point with ethylene. Hydrogen is added to control molecular weight.Temperature in the vessel is controlled to set-point by varying thejacket water temperature on the vessel. Prior to polymerization, thevessel is heated to the desired run temperature and the catalystcomponents: Titanium:(N-1,1-dimethyl-ethyl)dimethyl(1-(1,2,3,4,5-eta)-2,3,4,5-tetramethyl-2,4-cyclopentadien-1-yl)silanaminato))(2-)N)-dimethyl,CAS# 135072-62-7, Tris(pentafluorophenyl)boron, CAS# 001109-15-5,Modified methylaluminoxane Type 3A, CAS# 146905-79-5, are flowcontrolled, on a mole ratio basis of 1/3/5 respectively, combined andadded to the vessel. After starting, the polymerization is allowed toproceed with ethylene supplied to the reactor as required to maintainvessel pressure. In some cases, hydrogen is added to the headspace ofthe reactor to maintain a mole ratio with respect to the ethyleneconcentration. At the end of the run, the catalyst flow is stopped,ethylene is removed from the reactor, 1000 ppm of Irganox™π1010anti-oxidant (a registered trademark of CIBA-GEIGY) is then added to thesolution and the polymer is isolated from the solution. The resultingpolymers are isolated from solution by either stripping with steam in avessel or by use of a devolatilizing extruder. In the case of the steamstripped material, additional processing is required in extruder likeequipment to reduce residual moisture and any unreacted styrene.

TABLE 1A Total Wt % Total Polymer Styrene Solvent Styrene H₂ Run inresidue Talc Sample loaded loaded Pressure Temp Added Time Solution Meltin Level Isolation No. lbs kg lbs kg Psig kPa ° C. Grams Hrs Wt. % IndexPolymer Wt % Method A 252 114 1320 599 42 290 60 0 2.8 11.5 0.18 81.7<2.5 Stm. Str*. C 839 381 661 300 105 724 60 53.1 4.8 11.6 2.6 45.5 0Extruder G 842 382 662 300 105 724 60 8.8 3.7 8.6 0.01 48.3 <1.0 Stm.Str*. H 1196 542 225 102 70 483 60 7.5 6.1 7.2 0.03 29.8 0 Extruder I252 114 1320 599 40 276 60 23 6.5 18.0 1.8 81.6 <2.0 Stm.Str*. *SteamStripped

Test parts and characterization data for the interpolymers and theirblends are generated according to the following procedures:

Compression Molding: Samples are melted at 190° C. for 3 minutes andcompression molded at 190° C. under 20,000 lb (9,072 kg) of pressure foranother 2 minutes. Subsequently, the molten materials are quenched in apress equilibrated at room temperature.

Density: The density of the samples is measured according to ASTM-D792.

Differential Scanning Calorimetry (DSC): A Dupont DSC-2920 is used tomeasure the thermal transition temperatures and heat of transition forthe interpolymers. In order to eliminate previous thermal history,samples are first heated to 200° C. Heating and cooling curves arerecorded at 10° C./min. Melting (from second heat) and crystallizationtemperatures are recorded from the peak temperatures of the endothermand exotherm, respectively.

Melt Shear Rheology: Oscillatory shear rheology measurements areperformed with a Rheometrics RMS-800 rheometer. Rheological propertiesare monitored at an isothermal set temperature of 190° C. in a frequencysweep mode. η is viscosity. η(100/0.1) is the ratio of viscositiesmeasured at 100 rad/sec and 0.1 rad/sec.

Mechanical Testing: Shore A hardness was measured at 23° C. followingASTM-D240. Flexural modulus is evaluated according to ASTM-D790. Tensileproperties of the compression molded samples were measured using anINSTRON™ 1145 tensile machine (a registered trademark of the InstronCorporation, Canton, Mass.) equipped with an extensiometer, at 23° C.unless otherwise indicated. ASTM-D638 samples are tested at a strainrate of 5 min.⁻¹. The average of four tensile measurements is given. Theyield stress and yield strain are recorded at the inflection point inthe stress/strain curve. The Energy at break is the area under thestress/strain curve.

Tensile Stress Relaxation: Uniaxial tensile stress relaxation wasevaluated using an INSTRON™ 1145 tensile machine (a registered trademarkof the Instron Corporation, Canton, Mass.). Compression molded film (˜20mil, 0.5 mm thick) with a 1″ gauge length was deformed to a strain levelof 50% at a strain rate of 20 min.⁻¹. The force required to maintain 50%elongation was monitored for 10 min. The magnitude of the stressrelaxation is defined as (f_(i)−f_(f)/f_(i)) where f_(i) is the initialforce and f_(f) is the final force.

Thermomechanical Analysis (TMA): Data were generated using a PerkinElmer TMA 7 series instrument. Probe penetration is measured to 1 mmdepth on 2 mm thick compression molded parts using a heating rate of 5°C./min and a load of 1 Newton.

TABLE 1B Interpolymer blend components Blend Conponent (I) (C) (H) (A)(G) Composition wt % atactic 8.2 10.3 1 8.6 3.7 Polystyrene wt %Styrene^(b) 69.9 43.4 29.3 69.4 47.3 wt % Ethylene^(b) 30.1 56.6 70.730.6 52.7 mol % Styrene^(b) 38.4 17.1 10 37.9 19.5 mol % Ethylene^(b)61.6 82.9 90 62.1 80.5 Molecular weight MFR, I₂ 1.83 2.62 0.03 0.18 0.01M_(n) × 10⁻³ 71 66.8 118.1 161.1 144.9 M_(w)/M_(n) 2.63 1.89 2.04 2.112.26 Physical Properties Density, g/cc 1.0175 0.9626 0.943 1.0352 0.9604Tm, ° C. — 49.6 71.3 N.D.^(a) 45.7 % Crystallinity — 4.8 14.7 N.D.^(a)4.7 Tc, ° C. — 22.1 58.1 N.D.^(a) 17.0 Tg (DSC) 24.7 ˜ −12 −17.2 24.2−12.7 Mechanical Properties (23° C.) Shore A 98 75 88 96 76 TensileModulus, 703.3 6.9 20 594.3 6.8 MPa Flexural Modulus, 620.6 69 62.1617.1 141.3 MPa Yield Stress, MPa 7.5 1.3 2.4 N.D.^(a) N.D.^(a) % Strain@ Break 248.3 475.3 377.5 257.8 337.8 Stress @ Break, 17.1 22.6 34.321.5 17.5 MPa Energy @ Break, 98.2 102.2 145.5 118.5 73.2 N · m % Stress93.5 38 30.2 92.9 26.2 Relaxation (50%/10 min.) Melt Rheology η × 10⁻⁵(0.1 1.01 1.05 16.6 6.53 31 rad/sec), Poise η(100/0.1) 0.14 0.15 0.16¹0.048 0.038 Tan δ (0.1 9.98 4.2 2.37 4.42 1.26 rad/sec) ¹ratio ofη(1.6)/η(0.1). ^(a)N.D. = not determined. ^(b)Amount of monomer residuein polymer chain.

EXAMPLES 1-3 Blends with Ethylene/α-Olefin Copolymers

Blend Preparation: Three blend compositions, examples 1, 2 and 3 areprepared from interpolymer (A) above and olefin polymer (B) in weightratios of 75/25, 50/50 and 25/75 with a Haake mixer equipped with aRheomix 3000 bowl. The blend components are first dry blended and thenfed into the mixer equilibrated at 190° C. Feeding and temperatureequilibration takes 3-5 minutes. The molten material is mixed at 190° C.and 40 rpm for 10 minutes.

The characterization data for these blends and the blend componentswhich form the comparative experiments for these data are given in Table2.

TABLE 2 Polymer EXAMPLE (A)¹* (B)²* 1 2 3 Blend Composition Wt. %Interpolymer (A) 100 0 75 50 25 Wt. % Olefinic Polymer (B) 0 100 25 5075 Mechanical Properties (23° C.) Shore A Hardness 96 74 96 91 81Tensile Modulus, MPa 594.3 11 558.5 75.2 18.6 Flexural Modulus, MPa617.1 34.5 327.5 82.1 47.6 % Strain @ Break 257.8 762.1 313.2 373.8625.9 Stress @ Break, MPa 21.5 17.1 25.9 15.6 14.9 Energy @ Break, N · m118.5 141 154.7 114.6 174.1 % Stress Relaxation 92.9 29.2 86.4 77.1 54.6Mechanical Properties (−10° C.) Tensile Modulus, MPa — 22.1 853.6 162.739.3 % Strain @ Break 18.6 >577³  182.1 279.9 >581³  Stress @ Break, MPa19.8 >15.8 35.8 28 30.7 Energy @ Break, N · m 9.6 >118.0³ 150 143.2>260.4³ Melt Rheology (190° C.) η × 10⁻⁵ (0.1 rad/sec), 6.53 0.9 3.842.33 1.36 Poise η(100/0.1) 0.048 0.2 0.063 0.099 0.15 Tan δ (0.1rad/sec) 4.42 10.4 2.43 4.35 6.51 * Not an example of the presentinvention. ¹Interpolymer A containing 69.4 wt. (38.4 mole) percentstyrene; I₂ of 0.18. ²Olefin polymer (B) is ENGAGE ™ EG8100, anethylene/octene copolymer commercially available from and a registeredtrademark of The Dow Chemical Company and having a density of 0.87 g/cm³and a melt Index of 1.0 (190° C.; 2.16 kg). ³Sample slipped duringtesting.

Table 2 shows that the blend composition examples 1, 2 and 3 all havegood mechanical integrity and strength performance as evidenced by thestress, strain and total energy at break. Of particular merit is theblend performance at −10° C., with high toughness being found. Thestress and total energy at break unexpectedly exceeds or equals that ofthe component polymers (A) and (B).

Further, the blends all show unexpectedly high levels of stressrelaxation compared to what would be anticipated from the componentbehavior and blend composition ratios. This property is desirable formany film applications.

The melt rheology data for the three blend examples show that the lowshear tan δ (a measure of low shear melt elasticity) and viscosity islower compared to what would be anticipated from the component behaviorand blend composition ratios. This translates into improvedprocessability in some applications.

EXAMPLES 4, 5 AND 6 Blends with Ethylene/α-Olefin Copolymers

Blend Preparation: Three blend compositions, examples 4, 5 and 6 areprepared from interpolymer (C) above and olefin polymer (B) in weightratios of 75/25, 50/50 and 25/75 with a Haake mixer equipped ma with aRheomix 3000 bowl. The blend components are first dry blended and thenfed into the mixer equilibrated at 190° C. Feeding and temperatureequilibration takes 3-5 minutes. The molten material is mixed at 190° C.and 40 rpm for 10 minutes.

The characterization data for these blends and the blend componentswhich form the comparative examples for these experiments are given inTable 3.

TABLE 3 Polymer EXAMPLE (C)¹* (B)²* 4 5 6 Blend Composition Wt. %Interpolymer (C) 100 0 75 50 25 Wt. % Olefinic Polymer (B) 0 100 25 5075 Mechanical Properties (23° C.) Shore A Hardness 75 74 73 72 74Tensile Modulus, MPa 6.9 11 8.3 9.7 11 Flexural Modulus, MPa 69 34.523.4 17.9 15.6 % Strain @ Break 475.3 762.1 503.7 546.5 691.7 Stress @Break, MPa 22.5 17.1 26.9 21 24.5 Energy @ Break, N · m 102.2 141 102.4108.9 146.9 Mechanical Properties (−10° C.) Tensile Modulus, MPa 12.122.1 20.3 12.9 6.1 % Strain @ Break 301.4 >577³  343.9 425.8 >596 Stress@ Break, MPa 18.1 >15.8³ 31.8 31.4 28.3 Energy @ Break, N · m 78.4>118.0³ 142.4 162.2 >203.4³ Melt Rheology (190° C.) η × 10⁵ (0.1rad/sec), 1.05 0.9 1.08 1.05 1.5 Poise η(100/0.1) 0.15 0.2 0.14 0.14 0.1Tan δ (0.1 rad/sec) 4.2 10.4 2.3 2.8 2.4 * Not an example of the presentinvention. ¹Interpolymer (C) containing 43.4 wt. (17.1 mole) percentstyrene; I₂ of 2.62. ²Olefin polymer (B) is ENGAGE ™ EG8100, anethylene/octene copolymer commercially available from and a registeredtrademark of The Dow Chemical Company and having a density of 0.87 g/cm³and a melt Index of 1.0 (190° C.; 2.16 kg). ³Sample slipped duringtesting.

Table 3 shows that the blend composition examples 4, 5 and 6 all havegood mechanical integrity and strength performance as evidenced by thestress, strain and total energy at break. Of particular merit is theblend performance at −10° C., with high is toughness being found. Thestress and total energy at break unexpectedly exceeds or equals that ofthe component polymers.

The melt rheology data for the three blend examples show, in particular,that the low shear tan δ (a measure of low shear melt elasticity) islower compared to what would be anticipated from the component behaviorand blend composition ratios. This translates into improvedprocessability in some applications, compared to the component polymers.

EXAMPLE 7 Blend with Ethylene/α-Olefin Copolymer

Blend Preparation: A blend composition, example 7, is prepared frominterpolymer (A) above and olefin polymer (D) in a weight ratio of 50/50with a Haake mixer equipped with a Rheomix 3000 bowl. The blendcomponents are first dry blended and then fed into the mixerequilibrated at 190° C. Feeding and temperature equilibration takes 3-5minutes. The molten material is mixed at 190° C. and 40 rpm for 10minutes.

The characterization data for the blend and the blend components whichform the comparative examples for these experiments are given in Table4.

TABLE 4 Polymer Example (A) *¹ (D) *² 7 Blend Composition Wt. %Interpolymer (A) 100 0 50 Wt. % Olefinic Polymer (B) 0 100 50 MechanicalProperties (23° C.) Shore A 96 68 87 Tensile Modulus, MPa 594.3 6.2119.3 Flexural Modulus, MPa 617.1 23.4 105.5 % Strain @ Break 257.8810.1 365.2 Stress @ Break, MPa 21.5 14.4 15.3 Energy @ Break, N.m 118.5124.1 118.5 % Stress Relaxation 92.9 27.5 79.2 Mechanical Properties(−10° C.) Tensile Modulus, MPa — — 126.9 % Strain @ Break 18.6 — 278.9Stress @ Break, MPa 19.8 — 28.1 Energy @ Break N.m 9.6 — 136.8 MeltRheology (190° C.) η × 10⁵ (0.1 rad/sec), Poise 6.53 1.67 2.55η(100/0.1) 0.048 0.13 0.087 Tan δ (0.1 rad/sec) 4.42 6.04 3.34 * Not anexample of the present invention ¹Interpolymer (A) is anethylene/styrene interpolymer containing 69.4 wt. (37.9 mole) percentstyrene; I₂ of 0.18. ²Olefin polymer (D) is ENGAGE ™ EG8100, anethylene/octene copolymer commercially available from and a registeredtrademark of The Dow Chemical Company and having a density of 0.87 g/cm³and a melt Index of 1.0 (190° C.; 2.16 kg).

Table 4 shows that the blend composition example has good mechanicalintegrity and strength performance as evidenced by the stress, strainand total energy at break. Of particular merit is the blend performanceat −10° C., with high toughness being found compared to the unmodifiedInterpolymer (A).

The blend shows an unexpectedly high level of stress relaxation comparedto what would be anticipated from the component behavior and blendcomposition ratio. This property is desirable for many filmapplications.

The melt rheology data for the blend example shows that the low shearviscosity and tan δ (a measure of low shear melt elasticity) is lowercompared to either component. This translates into improvedprocessability in some applications, compared to the component polymers.

EXAMPLE 8 Blend with Ethylene/α-Olefin Copolymer

Blend Preparation: A blend composition, example 8, is prepared frominterpolymer (C) above and olefin polymer (E) in a weight ratio is of50/50 with a Haake mixer equipped with a Rheomix 3000 bowl. The blendcomponents are first dry blended and then fed into the mixerequilibrated at 190° C. Feeding and temperature equilibration takes 3-5minutes. The molten material is mixed at 190° C. and 40 rpm for 10minutes.

The characterization data for the blend and the blend components whichform the comparative examples for these experiments are given in Table5.

TABLE 5 Polymer Example (C) *¹ (E) *² 8 Blend Composition Wt. %Interpolymer (C) 100 0 50 Wt. % Olefinic Polymer (E) 0 100 50 MechanicalProperties (23° C.) Shore A 75 89 86 Tensile Modulus, MPa 6.9 76.5 29.6Flexural Modulus, MPa 69 129.6 105.5 % Strain @ Break 475.3 643.3 551.1Stress @ Break, MPa 22.5 35.6 32 Energy @ Break, N.m 102.2 289.5 183.7Melt Rheology (190° C.) η × 10⁻⁵ (0.1 rad/sec), Poise 1.05 1.19 —η(100/0.1) 0.15 0.13 — Tan δ (0.1 rad/sec) 4.2 5.12 — * Not an exampleof the present invention. ¹Interpolymer (C) is an ethylene/styreneinterpolymer containing 43.4 wt. (17.1 mole) percent styrene; I₂ of2.62. ²Olefin polymer (E) is AFFINITY ™ PL1880, an ethylene/octenecopolymer commercially available from and a registered trademark of TheDow Chemical Company and having a density of 0.903 g/cm3 and a meltIndex of 1.0 (190° C.; 2.16 kg).

Table 5 shows that the blend composition example has good mechanicalintegrity and strength performance as evidenced by the stress, strainand total energy at break.

EXAMPLES 9, 10 AND 11 Blends with Ultra-Low Molecular Weight Ethylene/αOlefin Copolymer

Preparation of Olefin Polymer F

Catalyst Preparation

Part 1: Preparation of TiCl₃(DME)_(1.5)

The apparatus (referred to as R-1) is set-up in the hood and purged withnitrogen; it consisted of a 10 L glass kettle with flush mounted bottomvalve, 5-neck head, polytetrafluoroethylene gasket, clamp, and stirrercomponents (bearing, shaft, and paddle). The necks are equipped asfollows: stirrer components are put on the center neck, and the outernecks had a reflux condenser topped with gas inlet/outlet, an inlet forsolvent, a thermocouple, and a stopper. Dry, deoxygenateddimethoxyethane (DME) is added to the flask (approx. 5 L). In thedrybox, 700 g of TiCl₃ is weighed into an equalizing powder additionfunnel; the funnel is capped, removed from the drybox, and put on thereaction kettle in place of the stopper. The TiCl₃ is added over 10minutes with stirring. After the addition is completed, additional DMEis used to wash the rest of the TiCl₃ into the flask. The additionfunnel is replaced with a stopper, and the mixture heated to reflux. Thecolor changed from purple to pale blue. The mixture is heated for 5hours, cooled to room temperature, the solid is allowed to settle, andthe supernatant is decanted from the solid. The TiCl₃(DME)_(1.5) is leftin R-1 as a pale blue solid.

Part 2: Preparation of [(Me₄C₅)SiMe₂N-t-Bu][MgCl]₂

The apparatus (referred to as R-2) is set-up as described for R-1,except that flask size is 30 L. The head is equipped with seven necks;stirrer in the center neck, and the outer necks containing condensertopped with nitrogen inlet/outlet, vacuum adapter, reagent additiontube, thermocouple, and stoppers. The flask is loaded with 4.5 L oftoluene, 1.14 kg of (Me₄C₅H)SiMe₂NH-t-Bu, and 3.46 kg of 2 M i-PrMgCl inEt₂O. The mixture is then heated, and the ether allowed to boil off intoa trap cooled to −78° C. After four hours, the temperature of themixture had reached 75° C. At the end of this time, the heater is turnedoff and DME is added to the hot, stirring solution, resulting in theformation of a white solid. The solution is allowed to cool to roomtemperature, the material is allowed to settle, and the supernatant isdecanted from the solid. The [(Me₄C₅)SiMe₂N-t-Bu] [MgCl]₂ is left in R-2as an off-white solid.

Part 3: Preparation of [(η⁵-Me₄C₅)SiMe₂N-t-Bu]TiMe₂

The materials in R-1 and R-2 are slurried in DME (3 L of DME in R-1 and5 L in R-2). The contents of R-1 are transferred to R-2 using a transfertube connected to the bottom valve of the 10 L flask and one of the headopenings in the 30 L flask. The remaining material in R-1 is washed overusing additional DME. The mixture darkened quickly to a deep red/browncolor, and the temperature in R-2 rose from 21° C. to 32° C. After 20minutes, 160 mL of CH₂Cl₂ is added through a dropping funnel, resultingin a color change to green/brown. This is followed by the addition of3.46 kg of 3 M MeMgCl in THF, which caused a temperature increase from22° C. to 52° C. The mixture is stirred for 30 minutes, then 6 L ofsolvent is removed under vacuum. Isopar E (6 L) is added to the flask.This vacuum/solvent addition cycle is repeated, with 4 L of solventremoved and 5 L of Isopar E added. In the final vacuum step, anadditional 1.2 L of solvent is removed. The material is allowed tosettle overnight, then the liquid layer decanted into another 30 L glasskettle (R-3). The solvent in R-3 is removed under vacuum to leave abrown solid, which is re-extracted with Isopar E; this material istransferred into a storage cylinder. Analysis indicated that thesolution (17.23 L) is 0.1534 M in titanium; this is equal to 2.644 molesof [(η⁵-Me₄C₅)SiMe₂N-t-Bu]TiMe₂. The remaining solids in R-2 are furtherextracted with Isopar E, the solution is transferred to R-3, then driedunder vacuum and re-extracted with Isopar E. This solution istransferred to storage bottles; analysis indicated a concentration of0.1403 M titanium and a volume of 4.3 L (0.6032 moles[(η⁵-Me₄C₅)SiMe₂N-t-Bu]TiMe₂). This gives an overall yield of 3.2469moles of [(η⁵-Me₄C₅)SiMe₂N-t-Bu]TiMe₂, or 1063 g. This is a 72% yieldoverall based on the titanium added as TiCl₃.

Polymer Preparation

The polymer is produced in a solution polymerization process using acontinuously stirred reactor. The polymer is stabilized with 1,250 ppmcalcium stearate, 500 ppm Irganox™ 1076 hindered polyphenol stabilizer(available from and a registered trademark of Ciba-Geigy Corporation),and 800 ppm PEPQ™ (tetrakis(2,4-di-t-butylphenyl)-4,4′-biphenylenediphosphonite) (available from and a registered trademark of ClariantCorporation).

The feed mixture of ethylene (2 lb/hr, 0.91 kg/hr) and the hydrogen(0.48 mole % ratio to ethylene) are combined into one stream beforebeing introduced into the diluent mixture, a mixture of C₈-C₁₀ saturatedhydrocarbons, e.g., Isopar™-E hydrocarbon mixture (available from and aregistered trademark of Exxon Chemical Company)employed in a wt. ratioto ethylene of 11.10:1; and the octene comonomer at a mole ratio toethylene of 12.50:1 is continuously injected into the reactor.

The metal complex at 4 ppm and 0.428 lb/hr (0.194 kg/hr) and cocatalystsat 88 ppm and 0.460 lb/hr (0.209 kg/hr) are combined into a singlestream and are also continuously injected into the reactor. The aluminumconcentration is 10 ppm at a flow rate of 0.438 lb/hr (0.199 kg/hr).

Sufficient residence time is allowed for the metal complex andcocatalyst to react prior to introduction into the polymerizationreactor. The reactor pressure is held constant at 475 psig. Ethylenecontent of the reactor, after reaching steady state, is maintained atthe conditions specified. The reactor temperature is 110° C. Theethylene concentration in the exit stream is 1.69 wt. Percent.

After polymerization, the reactor exit stream is introduced into aseparator where the molten polymer is separated from the unreactedcomonomer(s), unreacted ethylene, unreacted hydrogen, and diluentmixture stream. The molten polymer is subsequently strand chopped orpelletized, and, after being cooled in a water bath or pelletizer, thesolid pellets are collected. The resultant polymer is an ultra lowmolecular weight ethylene/octene copolymer having a density of 0.871g/cm³, melt viscosity of 4,200 centipoise (4.2 Pa.s) at 350° F. (176.7°C.), and number average molecular weight (Mn) of 9,100 and Mw/Mn of1.81.

Blend Preparation: Three blend compositions, examples 9, 10 and 11 areprepared from interpolymers (A), (G) and (H) above and olefin polymer(F) all in a weight ratio of 90/10 Interpolymer/olefin polymer with aHaake mixer equipped with a Rheomix 3000 bowl. The blend components arefirst dry blended and then fed into the mixer equilibrated at 190° C.Feeding and temperature equilibration takes 3-5 minutes. The moltenmaterial is mixed at 190° C. and 40 rpm for 10 minutes.

The characterization data for these blends and the blend componentswhich form the comparative examples for these experiments are given inTable 6.

TABLE 6 Polymer Ex. Polym Ex. Polym Ex. (A)*¹ (F)*² 9 (G)*³ 10 (H)*⁴ 11Blend Composition Wt. % Interpolymer (A) 100 0 90 0 0 0 0 Wt. %Interpolymer (G) 0 100 0 100 90 0 0 Wt. % Interpolymer (H) 0 0 0 0 0 10090 Wt. % Olefinic Polymer F 0 0 10 10 0 10 Mechanical Properties (23°C.) Shore A Hardness 96 — 97 76 72 88 84 Tensile Mod, MPa 594.3 7.55105.7 6.8 7.6 20 20.7 Flexural Mod, MPa 617.1 — 111 141.3 33.1 62.1 53.1% Strain @ Break 257.8 <75 254.2 337.8 515.9 377.5 341.7 Stress @ Break,MPa 21.5 <1.5 22.9 17.5 18 34.3 16.9 Energy @ Break, N · m 118.5 — 111.173.2 94 145.5 92.6 % Stress Relaxation (50%/10 min) 92.9 — 90 26.2 35.930.2 30.9 Melt Rheology (190° C.) η × 10⁵ (0.1 rad/sec), poise 6.53 —5.3 31 0.92 16.6 11 η(100/0.1) 0.048 — 0.046 0.038 0.09 0.16 0.046 Tan δ(0.1 rad/sec) 4.42 — 3.74 1.26 3.12 2.37 2.17 * Not an example of thepresent invention. ¹Interpolymer (A) containing 69.9 wt. (40 mole)percent styrene; I₂ of 1.83. ²Olefin polymer (F) is an ultra lowmolecular weight ethylene/1-octene copolymer having a density of 0.871g/cm³, melt viscosity of 4,200 centipoise (4.2 Pa · s) at 350° F.(176.7° C.), number average molecular weight (Mn) of 9,100 and Mw/Mn of1.81. ³Interpolymer (G) containing 47.3 wt. (19.5 mole) percent styrene;I₂ of 0.01. ⁴Interpolymer (H) containing 29.3 wt. (10 mole) percentstyrene; I₂ of 0.03.

First, this low molecular weight olefin polymer(F) has little mechanicalstrength compared to a high molecular weight analogue. Table 6 showsthat the blend composition examples retain the good mechanical integrityand strength performance of the component polymers as evidenced by thestress, strain and total energy at break.

The blend shows an unexpectedly high level of stress relaxation comparedto what would be anticipated from the component behavior and blendcomposition ratio. This property is desirable for many filmapplications. The melt rheology data for the blend examples show thatthe low shear viscosity and tan δ (a measure of low shear meltelasticity) can be altered by incorporation of olefin polymer (F). Thistranslates into improved processability in some applications, comparedto the component polymer, but with retention of desirable mechanicalperformance.

EXAMPLES 12 AND 13 Blends with Chlorinated Polyethylene(CPE)

Blend Preparation: Two blend compositions, examples 12 and 13 areprepared from interpolymers (I) and (C) and olefin polymer (J) both in aweight ratio of 50/50 with a Haake mixer equipped with a Rheomix 3000bowl. The blend components are first dry blended and then fed into themixer equilibrated at 190° C. Feeding and temperature equilibrationtakes 3-5 minutes. The molten material is mixed at 190° C. and 40 rpmfor 10 minutes.

The characterization data for these two blends and the blend componentswhich form the comparative examples for these experiments are given inTable 7.

TABLE 7 Polymer Ex. Poly. Ex. (I)*¹ (J)*² 12 (C)*³ 13 Blend CompositionInterpolymer (C) 0 0 0 100 50 Interpolymer (I) 100 0 50 0 0 OlefinPolymer (J) 0 100 50 0 50 Mechanical Properties (23° C.) TensileModulus, MPa 703.3 28.2 206.4 6.6 11.9 % Strain @ Break 248.3 370.2319.9 475.3 566.1 Stress @ Break, MPa 17.1 6 14.2 22.5 12 Energy @Break, N · m 98.2 41.4 75.1 102.2 77.6 Melt Rheology (190° C.) η × 10⁻⁵(0.1 rad/sec), poise 1.01 — 5.3 1.05 0.92 η(100/0.1) 0.14 9.98 0.0460.15 0.09 Tan δ (0.1 rad/sec) 9.98 — 3.74 4.2 3.12 * Not an example ofthe present invention. ¹Interpolymer (C) containing 43.3 wt. (17.1 mole)percent styrene; I₂ of 2.62. ²Olefin polymer (J) is chlorinatedpolyethylene (CPE) commercially available from and a registeredtrademark of The Dow Chemical Company as TYRIN ™ 4211P, and having achlorine content of 42%, a density of 1.22 g/cm³ and <2% residualcrystallinity as measured by heat of fusion. ³Interpolymer (I)containing 69.9 wt. (38.4 mole) percent styrene; I₂ of 1.83.

Table 7 shows that the blend composition examples have good mechanicalintegrity and strength performance as evidenced by the stress, strainand total energy at break.

EXAMPLES 14 TO 22 Blends with Polypropylene and Propylene Copolymers

Blend Preparation: All blend compositions are prepared with a Haakemixer equipped with a Rheomix 3000 bowl. The blend components are firstdry blended in the ratios given in Table 8 and then fed into the mixerequilibrated at 190° C. Feeding and temperature equilibration takes 3-5minutes. The molten material is mixed at 190° C. and 40 rpm for 10minutes.

The characterization data for the blends and the blend components whichform the comparative examples for these experiments are given in Table8.

TABLE 8 Poly. Poly. Poly. Ex. Ex. Poly. Poly. Poly. Ex. Ex. Ex. (G)*¹(I)*² K*³ 14 15 (G)*¹ (I)*² L³ 16 17 18 Blend Composition Interpolymer(G) 100 0 0 0 50 100 0 0 0 0 50 Interpolymer (I) 0 100 0 70 0 0 100 0 7050 0 Olefinic Polymer K 0 0 100 30 50 0 0 100 30 50 50 MechanicalProperties (23° C.) Tensile Mod, MPa 6.8 703.3 1,203.2 1,463.1 3,055.9111 542.6 410.3 62.1 % Strain @ Break 337.8 248.3 1.7 125.3 2 693 249.723.6 390.2 Stress @ Break, MPa 17.5 17.1 11.3 13.7 18.2 6.7 14.1 9.510.8 Energy @ Break, 73.2 98.2 0.5 63.9 1.1 120.8 96.8 7.7 114.4 N · mTMA⁴, ° C. — 66 164 114 162 — 66 139 78 126 129 Melt Rheology (190° C.)η × 10⁻⁵ (0.1 rad/sec), 31 1.01 0.62 0.87 0.79 0.88 0.95 0.87 8.45 poiseη(100/0.1) 0.038 0.14 0.052 0.1 0.071 0.062 0.1 0.091 0.018 Tan δ (0.1rad/sec) 1.26 9.98 3.06 3.5 3.89 3.26 3.08 3.67 0.75 Poly. Poly. Poly.Ex. Ex. Poly. Ex. Ex. (G)*¹ (I)*² (M)*³ 19 20 (N)*⁴ 21 22 BlendComposition Interpolymer (G) 100 0 0 0 50 0 0 50 Interpolymer (I) 0 1000 70 0 0 50 0 Olefinic Polymer (M) 0 0 100 30 50 0 0 0 Olefinic Polymer(N) 0 0 0 0 0 100 50 50 Mechanical Properties (23° C.) Tensile Mod, MPa6.8 703.3 20 406.8 11.7 2 84.8 3.5 % Strain @ Break 337.8 248.3 717.3309 327.5 181.8 29.7 284.7 Stress @ Break, MPa 17.5 17.1 8.3 16 5.5 0.22.2 2.3 Energy @ Break, N · m 73.2 98.2 105.1 112.3 43.8 1.8 2.6 14.4Melt Rheology (190° C.) η × 10⁻⁵ (0.1 rad/sec), 31 1.01 0.9 1.03 3 1.771.3 6.11 poise η(100/0.1) 0.038 0.14 0.19 0.13 0.057 0.14 0.13 0.031 Tanδ (0.1 rad/sec) 1.26 9.98 7.11 3.12 1.7 4.83 3.68 0.94 * Not an exampleof the present invention. ¹Interpolymer (G) containing 47.3 wt. (19.5mole) percent styrene; I₂ of 0.01. ²Interpolymer (I) containing 69.9 wt.(38.4 mole) percent styrene; I₂ of 1.83. ³Olefin polymer (M) is anethylene-propylene copolymer containing 76% Ethylene/24% Propylene,produced via INSITE ™ catalyst technology (a registered trademark of theDow Chemical Co.) and having a melt index (I₂) of 1.37. ⁴Olefin polymer(N) is an ethylene-propylene-diene terpolymer containing 50.9%Ethylene/44.9% Propylene/4.2% norbornene, produced via INSITE ™ catalysttechnology (a registered trademark of the Dow Chemical Co.) and having amelt index (I₂) of 0.56.

Table 8 shows that blend compositions show good mechanical integrity andstrength performance as evidenced by the stress, strain and total energyat break.

EXAMPLES 23, 24 AND 25 Blends with Ethylene/Vinyl Acetate Copolymer

Blend Preparation

Three blend compositions, examples 23, 24 and 25, are prepared in aweight ratios of 50/50 from interpolymer (H) and olefin polymer (O),Elvax™ 250, (a registered trademark of Du Pont) a weight ratio of 50/50from interpolymer(G) and olefin polymer (O), and a weight ratio of 50/50from interpolymer (A) and olefin polymer (O), with a Haake mixerequipped with a Rheomix 3000 bowl. The blend components are first dryblended and then fed into the mixer equilibrated at 190° C. Feeding andtemperature equilibration takes 3-5 minutes. The molten material ismixed at 190° C. and 40 rpm for 10 minutes.

The characterization data for these blends and the blend componentswhich form the comparative experiments are given in Table 9.

TABLE 9 Poly. Poly. Ex. Poly. Example (H)² (O)⁴ 23 (G)² Ex. 24 Poly.(A)¹ Ex. 25 Blend Composition. (H)/(O) (G)/(O) (A)/(O):50/50 Wt. ratio50/50 50/50 Mechanical properties (23° C.) Tensile Mod, MPa 20 14.5 19.36.8 10.3 594.3 93.8 % Strain @ Break 377.5 1019 465 337.8 577 257.8 297Stress @ Break, MPa 34.3 11 13.9 17.5 7.4 21.5 11.3 Energy @ Break,145.5 146.5 78.6 73.2 61 118.5 55.6 N · m Melt Rheology (@ 190° C.) η10⁻⁵ (0.1 rad/sec), 16.6 0.5 3.3 31 0.23 6.53 0.87 poise η(100/0.1) —0.38 0.052 0.038 0.14 0.048 0.076 Tan δ (0.1 rad/sec) 2.37 48.3 2.031.26 3.9 4.42 5.2 ¹Interpolymer (A) containing 69.4 wt. (38.4 mole)percent styrene; I₂ of 0.18. ²Interpolymer (G) containing 47.3 wt. (19.5mole) percent styrene; I₂ of 0.01. ³Interpolymer (H) containing 29.3 wt.(10 mole) percent styrene; I₂ of 0.03. ⁴Polymer (O) is an ethylene/vinylacetate copolymer, Elvax ™ 250 available from and a registered trademarkof the DuPont chemical company.

Table 9 shows that the blend composition examples have good mechanicalintegrity and strength performance as evidenced by the stress, strainand total energy at break.

The melt rheology data for the blend examples show that the low shearviscosity and tan δ (a measure of low shear melt elasticity) can beunexpectedly altered by incorporation of the interpolymers. Thistranslates into improved processability in some applications, comparedto the component polymer, but with retention of desirable mechanicalperformance.

EXAMPLE 26

LDPE Polymer

The LDPE polymer used in this example has a melt index of 1.8 per ASTM1238,at 190° C./2.16 kg and a density of 0.923 g/cm³.

ES Interpolymer

The ES interpolymer employed in this example is interpolymer I (seetables 1A and 1B).

The resultant interpolymer contains 69.9 wt. percent (38.4 mol percent)styrene moiety (residue) and a melt index (I)₂ of 1.83.

The equipment used in this example is a 38 mm (1½″) screw type extruderhaving additional zones of mixing and cooling at the end of usualsequential zones of feeding, metering, and mixing. An opening forblowing agent is provided on the extruder barrel between the meteringand mixing zones. At the end of the cooling zone, there is attached adie orifice having an opening of rectangular shape. The height of theopening, hereinafter called the die gap, is adjustable while its widthis fixed at 6.35 mm (0.25″)

In this example, 80/20 and 60/40 blends of a low density polyethylene(LDPE) and an ES copolymer are expanded with isobutane blowing agent.For comparison, a foam is also prepared from the straight LDPE resin.

The granular polyethylene is preblended with a predetermined amount ofthe granular ES copolymer, a concentrate of glycerol monostearate (GMS)so that the effective GMS level could be 1.0 pph, and a small amount(approximately 0.02 pph) of talcum powder. GMS is added for foamdimensional stability and talcum powder is added for cell size control.The solid mixture is then fed into the hopper of the extruder andextruded at a uniform rate of 15 lb/hr) (6.8 kg/hr). The temperaturesmaintained at the extruder zones are 160° C. at feeding zone, 177° C. attransition zone, 188° C. at melting zone, 193° C. at metering zone and177° C. at mixing zone. Isobutane is injected into the injection port ata uniform rate so that the blowing agent level became approximately 1.3g-moles per kilogram of polymer (mpk). The temperature of the coolingzone is gradually reduced to cool the polymer/blowing agent mixture(gel) to the optimum foaming temperature. The optimum foamingtemperature ranged from 108° C. to 111° C. The die temperature ismaintained at 108-109° C. throughout the tests in this example. The dieopening is adjusted to achieve a good foam strand free from prefoaming.

Processability and Strength Testing

The processability data of the tests are summarized in Table 10. Goodfoams having low densities and substantially closed-cell structure areachieved from the polymer bends as well as from the LDPE resin. Theblends permit greater die openings and thus larger is foamcross-sectional sizes. All foams have a width of approximately 32 mm.The foams are dimensionally stable during aging at a room temperaturewhile exhibiting little shrinkage. The strength properties of the foamsare tested approximately one month after extrusion. As shown in Table10, the foams made from LDPE/ES blends are stronger and tougher than theLDPE foam in both tensile and compression tests.

TABLE 10 Processability and Strength Properties of Blend Foams FoamTens. Comp. Polymer Die Gap Thick. Dens. Cell Size Tens. Str. Elong.Str. Type (mm) (mm) (kg/m³ (mm) (kPa) (%) (kPa) Test No. (1) (2) (3) (4)(5) (6) (7) (8) 1.1* LDPE 1.5 11 30 1.8 193 58 40 1.2 LDPE/ES 1.8 15 351.5 200 71 53 80/20 1.3 LDPE/ES 2.4 17 36 1.1 214 134 68 60/40 * Not anexample of this invention. (1) ES = ethylene/styrene copolymer I having69.9% styrene residue and a melt index (I₂) of 1.83. (2) The height ofdie opening at the threshold of prefoaming in millimeters. (3) Thethickness of foam body in millimeters. (4) The density of foam body agedfor 4 weeks in kilograms per cubic meter. (5) The cell size determinedper ASTM D3576 in millimeters. (6) Tensile strength of the foam body inthe extrusion direction in kilopascals. (7) Tensile elongation of thefoam body in the extrusion direction in percent. (9) Compressivestrength of the foam body at 25% deflection determined per ASTM D3575 inkilopascals.

Damping Characteristics

The foams prepared above are tested for their damping characteristics.The test specimens are prepared from foam strands made above by cuttingthem into strips of approximately 12.7 mm in width, 4.5 mm in thicknessand 51 mm in length. The damping tests are conducted on a dynamicmechanical spectrometer operated in a oscillatory torsional mode. Inpractice, a specimen is mounted on a torsional test jig so that thelength between the clamps could be approximately 45 mm. At an ambienttemperature of approximately 25° C., the specimen is twisted toapproximately 0.5% strain in a back-and-forth oscillatory motion at aspeed of one radian per second at the start. The speed of oscillation isgradually increased until it reached 100 radians per second where thetest is terminated. During the frequency scan, there are recorded thestorage modulus (G′), the loss modulus (G″), tan 6 and the dampingcoefficient (C). The latter two properties are related to the formerproperties and the oscillating speed by the following equations:$\begin{matrix}{{\tan \quad \delta} = \frac{G^{''}}{G^{\prime}}} & (1) \\{C = \frac{G^{''}}{\omega}} & (2) \\{\omega = {2\pi \quad f}} & (3)\end{matrix}$

where, ω is the angular speed in radians per second and f, the frequencyin Hertz (Hz).

Two specimens are tested per each foam. In Table 11, the excerpted dataat one Hz and 10 Hz are presented. The data are the average of valuesfor two runs. In addition, the damping coefficients for the entire rangeof frequency are shown in Table 12. It is evident from the table thatthe LDPE/ES blend foams are superior to the LDPE foam in damping orenergy-absorbing capabilities. That is, the foams have greater G′, G″,tan δ, and C than the control LDPE foam. The enhancement of theenergy-absorbing capability with the level of the ES copolymer is alsoevident. The 60/40: LDPE/ES blend foam is remarkable with its five foldbetter damping capability than the LDPE foam.

TABLE 11 Damping Characteristics for Various Acoustical Blend Foams 1 Hz(6.3 rad/sec) 10 Hz (63 rad/sec) Test Polymer G′ G″ Tan δ C G′ G″ Tan δC No. Type (1) (2) (3) (4) (1) (2) (3) (4) 1.1* LDPE 40  6 0.14 0.9 46 6 0.13 0.1 1.2 LDPE/ES 63 12 0.19 1.9 78 12 0.15 0.2 80/20 1.3 LDPE/ES85 30 0.35 4.7 30 31 0.24 0.5 60/40 * Not an example of this invention(1) Storage modulus in E⁺⁹ dyne per square centimeter. (2) Loss modulusin E⁺⁹ dyne per square centimeter. (3) tan delta = G″/G′. (4) Dampingcoefficient in E⁺⁹ dyne per square centimeter/radians per second.

TABLE 12 Effect of Frequency on Damping Coefficients of VariousAcoustical Blend Foams in Torsional DMS Test Damping Coefficient Freq-Ang. E⁺⁹ dyne sec/cm² Test uency Vel. LDPE/ES LDPE/ES No. Hz rad/s LDPE80/20 60/40 a 0.16 1.00 5.43 11.60 21.65 b 0.20 1.26 4.41 9.37 18.25 c0.25 1.59 3.58 7.55 15.4 d 0.32 2.00 2.8 6.10 12.85 e 0.40 2.51 2.324.86 10.75 f 0.50 3.16 1.81 3.70 8.82 g 0.63 3.98 1.42 3.04 7.24 h 0.805.01 1.12 2.48 5.84 i 1.00 6.31 0.90 1.93 4.72 j 1.26 7.94 0.70 1.523.84 k 1.59 10.00 0.56 1.17 3.06 l 2.01 12.60 0.43 0.85 2.48 m 2.5315.90 0.36 0.74 1.96 n 3.18 20.00 0.27 0.58 1.57 o 3.99 25.10 0.22 0.481.24 p 5.03 31.80 0.19 0.38 0.98 q 6.33 39.80 0.14 0.30 0.77 r 7.9750.10 0.11 0.24 0.62 s 10.04 63.10 0.09 0.18 0.49 t 12.64 79.40 0.080.15 0.39 u 15.92 100.00 0.06 0.13 0.31

Dynamic Cushioning Testing

As shown in the tests of this example, the LDPE/ES blend foams manifesttheir superior energy absorbing capabilities in dynamic cushioning aswell. In this example, the foams made above are prepared into drop testspecimens of approximately 2″ (5.08 cm) cubes. Several foam strands arecut and heat-welded together to prepare the test specimens. A specimenis set on a table so that its vertical direction (of the foam strand) isaligned vertically. A weight is dropped onto the specimens from anapproximately 61 cm (24″) height. An accelerometer adhered on the top ofthe weight records the deceleration of the weight by the foam specimen.Four additional drops are made on the same specimen with one-minuteInterval given between the drops. The tests are repeated with anotherweight with a new specimen. Weights are selected to exert a staticstress ranging from approximately 1.8 kPa to 13.4 kPa. The thickness ofthe foam specimen before and after the drop tests are recorded.

The data are summarized in Table 13. In general, the LDPE/ES blendfoams, are shown to be better shock mitigating materials that the LDPEfoam. The blend foams give a lower minimum peak deceleration. Theshock-mitigating capability of the LDPE/ES: 60/40 blend foam isespecially remarkable as the foam records a low peak deceleration at awide range of static loading. All foams recovered well after the droptests as the recovery data for a heavy weight in Table 13 indicate.

TABLE 13 Dynamic Cushioning Properties Recovery Peak Deceleration atStatic 9.3 kPa Stress (kPa) after Test Polymer (1) 1 hr No. Type 1.8 2.43.4 6.0 9.3 13.4 (2) 1.1* LDPE 65 56 57 60 89 N.D.³ 95 1.2 LDPE/ES 59 5854 60 99 N.D.³ 95 80/20 1.3 LDPE/ES 62 62 51 55 60 81 96 60/40 * Not anexample of this invention. 1 The average of peak decelerations duringsecond through fifth drops in Gs. 2 Thickness as a percentage of theinitial one hour after the drop tests with the loading of 9.3 kPa. 3 NotDetermined.

EXAMPLE 27

LDPE Polymer

The LDPE polymer used in this example has a melt index of 1.8 per ASTM1238 at 190° C./2.16 kg and a density of 0.923 g/cm³.

ES Interpolymer

The ES interpolymer employed in this example is prepared in a mannersimilar to that of interpolymer C and contains 45.9 wt. (18.3 mol)percent styrene moiety and a melt index (I₂) of 0.43.

The apparatus and the method of preparation of the foam are essentiallythe same as in Example 26. A good-quality foam of a substantially closedcell structure is made from the blend. The foam has a thickness of 19mm, width of 34.5 mm, density of 29 kg/m³ and cell size of 1.2 mm.

The dynamic mechanical properties of the foam are determined using aforced vibration apparatus (MTS 831 Elastomer Test System). In the test,a rectangular specimen is cyclically compressed with a predetermineddynamic load at a certain frequency and the dynamic strain induced inthe specimen is monitored. In practice, a rectangular specimen of 32.9mm in width, 34.6 mm in depth and 6.5 is mm in height is cut out of theextruded foam strand and subjected to a dynamic mechanical test in atemperature-controlled chamber. The temperature of the chamber ismaintained at −10° C. The mean load is set at −20 Newtons and thedynamic load is set at 15 Newtons. The frequency (f) of cycliccompression is sweeped from 1 Hz to 101 Hz at a 2 Hz step.

From the dynamic stiffness (K*), phase angle (δ) and shape factor,storage modulus of elasticity (E′), loss modulus of elasticity (E″) anddamping coefficient of the foam specimen are calculated by the followingequations: $\begin{matrix}{{{shape}\quad {factor}} = \frac{{width} \times {depth}}{height}} & \text{(A1)} \\{E^{\prime} = \frac{K^{''} \times \cos \quad \delta}{shapefactor}} & \text{(A2)} \\{E^{''} = \frac{K^{''} \times \sin \quad \delta}{shapefactor}} & \text{(A3)} \\{C = {\frac{K^{''}\sin \quad \delta}{2\pi \quad f} = \frac{E^{''} \times {shapefactor}}{2\pi \quad f}}} & \text{(A4)}\end{matrix}$

The foam made in Test 1.1 of Example 23 is similarly tested forcomparison. The specimen of the Test 1.1 foam has a width of 32 mm,depth of 35.2 mm and height of 6.8 mm. The data for these two foamspecimens at selected frequencies of 1, 11 and 101 Hz are set forth inTable 13.

TABLE 14 At 1 Hz At 11 Hz At 101 Hz tan tan Test E′ E″ δ C E′ E″ tan δ CE′ E″ δ C No. (1) (2) (3) (4) (1) (2) (3) (4) (1) (2) (3) (4) 1.1* 10.60.23 0.21 5.93 1.36 0.23 0.17 0.54 1.62 0.26 0.18 0.07 4 1.29 0.35 0.279.71 1.90 0.38 0.20 0.96 2.66 0.43 0.16 0.12 * Not an example of thisinvention (1) storage modulus in N/mm². (2) loss modulus in N/mm². (3)E″/E′ (4) Damping coefficient in N-sec/mm. From Table 143, it is evidentthat the LDPE/ES (465) blend foam has the better damping capability thanan LDPE foam at −10° C.

EXAMPLE 28

In this example, 10 grams of a ethylene-styrene (ES) copolymer that isused in Example 23 (ethylene-styrene copolymer (I); see table 1A & 1B)is melt blended with 10 grams of an ethylene-acrylic acid copolymer(EAA) available from and a registered trademark of is The Dow ChemicalCompany as Primacor™ 3340 (6.5 wt. % acrylic acid and 9 melt index)using a Brabender mixer. The mixing is done at 180° C. for 15 minutes ata rotor rotating speed of 30 rpm. The polymer blend is molded on to asteel bar maintained at 180° C. using a hot press in order to determineits damping capability in accordance with the SAE J1637 test. The steelbar has the dimensions of 0.8 mm in thickness, 12.7 mm in width and 225mm in length. Approximately a 200 mm length of the steel bar is coveredwith the polymer layer of uniform thickness of approximately 1.2 mm.Adhesion between the steel bar and the polymer layer is excellent. Forcomparison, a steel bar specimen coated with pure Primacor™ 3340 resinof approximately 1.2 mm thickness is also prepared.

The specimens are tested according to the SAE J1637 test for theirdamping capabilities at an ambient temperature of 23° C. The specimencoated with an EAA/ES layer recorded a damping ratio (factor) of 0.79%.This damping ratio is compared with the damping ratio of a bare steelbar (0.13%) and that of a steel bar adhered with a pure EAA layer(0.59%).

EXAMPLES 29-31

The resins in Table 15 were employed in the following Examples 29-31.The LDPE used was that used in Example 26 and had a melt index, I₂, of1.8 g/10 min and a density of 0.923 g/cm³. The ethylene styreneinterpolymers ESI #'s 1 through 4 were prepared as follows:

Reactor Description

The single reactor used was a 6 gallon (22.7 L), oil jacketed, Autoclavecontinuously stirred tank reactor (CSTR). A magnetically coupledagitator with Lightning A-320 impellers provides the mixing. The reactorran liquid full at 475 psig (3,275 kPa). Process flow was in the bottomand out the top. A heat transfer oil was circulated through the jacketof the reactor to remove some of the heat of reaction. After the exitfrom the reactor was a micromotion flow meter that measured flow andsolution density. All lines on the exit of the reactor were traced with50 psi (344.7 kPa) steam and insulated.

Procedure

Ethylbenzene or toluene solvent was supplied to the mini-plant at 30psig (207 kPa). The feed to the reactor was measured by a FMicro-Motionmass flow meter. A variable speed diaphragm pump controlled the feedrate. At the discharge of the solvent pump a side stream was taken toprovide flush flows for the catalyst injection line (1 lb/hr (0.45kg/hr)) and the reactor agitator (0.75 lb/hr (0.34 kg/hr)). These flowswere measured by differential pressure flow meters and controlled bymanual adjustment of microflow needle valves. Uninhibited styrenemonomer was supplied to the mini-plant at 30 psig (207 kpa). The feed tothe reactor was measured by a Micro-Motion mass flow meter. A variablespeed diaphragm pump controlled the feed rate. The styrene streams wasmixed with the remaining solvent stream. Ethylene was supplied to themini-plant at 600 psig (4,137 kPa). The ethylene stream was measured bya Micro-Motion mass flow meter just prior to the Research valvecontrolling flow. A Brooks flow meter/controllers was used to deliverhydrogen into the ethylene stream at the outlet of the ethylene controlvalve. The ethylene/hydrogen mixture combines with the solvent/styrenestream at ambient temperature. The temperature of the solvent/monomer asit enters the reactor was dropped to ˜5° C. by an exchanger with −5° C.glycol on the jacket. This stream entered the bottom of the reactor. Thethree component catalyst system and its solvent flush also enter thereactor at the bottom but through a different port than the monomerstream. Preparation of the catalyst components took place in an inertatmosphere glove box. The diluted components were put in nitrogen paddedcylinders and charged to the catalyst run tanks in the process area.From these run tanks the catalyst was pressured up with piston pumps andthe flow was measured with Micro-Motion mass flow meters. These streamscombine with each other and the catalyst flush solvent just prior toentry through a single injection line into the reactor.

Polymerization was stopped with the addition of catalyst kill (watermixed with solvent) into the reactor product line after the micromotionflow meter measuring the solution density. Other polymer additives canbe added with the catalyst kill. A static mixer in the line provideddispersion of the catalyst kill and additives in the reactor effluentstream. This stream next entered post reactor heaters that provideadditional energy for the solvent removal flash. This flash occured asthe effluent exited the post reactor heater and the pressure was droppedfrom 475 psig (3,275 kPa) down to ˜250mm of pressure absolute at thereactor pressure control valve. This flashed polymer entered a hot oiljacketed devolatilizer. Approximately 85 percent of the volatiles wereremoved from the polymer in the devolatilizer. The volatiles exit thetop of the devolatilizer. The stream was condensed and with a glycoljacketed exchanger, entered the suction of a vacuum pump and wasdischarged to a glycol jacket solvent and styrene/ethylene separationvessel. Solvent and styrene were removed from the bottom of the vesseland ethylene from the top. The ethylene stream was measured with aMicro-Motion mass flow meter and analyzed for composition. Themeasurement of vented ethylene plus a calculation of the dissolvedgasses in the solvent/styrene stream were used to calculate the ethyleneconversion. The polymer seperated in the devolatilizer was pumped outwith a gear pump to a ZSK-30 devolatilizing vacuum extruder. The drypolymer exits the extruder as a single strand. This strand was cooled asit was pulled through a water bath. The excess water was blown from thestrand with air and the strand was chopped into pellets with a strandchopper.

In all cases the three component catalyst stream employed modifiedmethylaluminoxane Type 3A, CAS# 146905-79-5. The catalyst used toprepare ESI #1 was(t-butylamido)dimethyl(tetramethylcyclopentadienyl)silane-titanium (II)1,3-pentadiene, and the cocatalyst was bis-hydrogenated tallowalkylmethylammonium tetrakis(pentafluorophenyl)borate.

The catalyst used to prepare ESI #'s 2, 3 and 4 wasdimethyl[N-(1,1-dimethylethyl)-1,1-dimethyl-1-[(1,2,3,4,5-.eta.)-1,5,6,7-tetrahydro-3-phenyl-s-indacen-1-yl]silanaminato(2-)-N]-titaniumand the cocatalyst was tris(pentafluorophenyl)boron, CAS# 001109-15-5.

The various process conditions and resulting interpolymer properties aresummarized in Table 15.

TABLE 15 Inter- Reactor MMAO/ Melt polymer % Temp Ti B/Ti Index PercentStyrene Resin ° C. Solvent Ratio Ratio (I₂) aPS wt % mol % ESI #1 85Ethylbenzene 6 1.2 1.0 14 38 17 ESI #2 93 Toluene 7 3.0 1.5 0.8 47 20ESI #3 79 Toluene 9 3.5 1.5 1.8 69 39 ESI #4 97 Toluene 3.5 3.5 10.0 0.231 11 Weight percent styrene in the interpolymer is the percent styreneincorporated in the interpolymer based upon the total weight of the ESIresin. Mole percent styrene in the interpolymer is the percent styreneincorporated in the interpolymer based upon the total moles of ESI resinPercent aPS is the percent atactic polystyrene based upon total weightof ESI resin I₂ is the melt index measured at 190° C. using a weight of2.16 kg

EXAMPLE 29

LDPE/ESI resin blend foams of the present invention were made todemonstrate the effect of ESI in broadening the observed foamingtemperature window versus that typically observed in making conventionalLDPE foams.

The LDPE/ESI resin blend foams were made in an apparatus comprising anextruder, a mixer, a cooler, and an extrusion die in series. Resingranules of the LDPE and ESI were dry tumble blended and fed via ahopper to the extruder. The ESI resin contained a small amount of thetalc. The granules were melted and blended to form a polymer melt. Thepolymer melt was fed to the mixer where isobutane, a blowing agent, wasincorporated to form a polymer gel. The polymer gel was conveyed throughthe cooler to lower the temperature of the gel to a desirable foamingtemperature. The cooled polymer gel is conveyed through the extrusiondie into a zone of lower pressure to form the expanded foam product.

Use of LDPE/ESI resin blends afforded a significant increase of thefoaming temperature window to 3-4° C. This increase is significant sincethe foaming window is typically only 1° C. for foams containing onlyLOPE resin. Expansion of the foaming window reduces the incidence of“freeze-off” (solidification of resin prior to exiting the extrusiondie) and production scrap generation. High quality, low density closedcell foams were produced without encountering freeze-off.

Based upon the results, useful ESI resins include those having 30-75weight percent total styrene content, melt index of 0.5-20, and up to 20weight percent aPS (atactic polystyrene) and preferably less than 2weight percent aPS. Total styrene content in the ESI resin is the weightof styrene incorporated in the ethylene/styrene interpolymer plus theweight of the free constituent aPS divided by the total weight of theESI resin. Results are set forth in Table 16 below.

TABLE 16 Type of % ESI ic4 % ESI inter- % Density pcf Open Cell Sample(phr) LDPE Resin polymer aPS T_(f) (° C.) (Kg/m³) Content Percent 1 7.580 ESI #2 19.8 0.2 108 2.43 (38.9) 4.4 2 7.5 80 ESI #2 19.8 0.2 106 2.37(37.9) 4.8 3 7.5 80 ESI #1 17.2 2.8 111 2.52 (40.3) 6.6 4 7.5 80 ESI #117.2 2.8 110 2.26 (36.2) 4.7 5 7.5 80 ESI #3 19.6 0.4 110 2.36 (37.8)5.8 6 7.5 80 ESI #3 19.6 0.4 109 2.22 (35.5) 3.2 7 7.5 80 ESI #3 19.60.4 108 2.26 (36.2) 2.9 8 7.5 80 ESI #3 19.6 0.4 107 2.33 (37.3) 3.1 97.5 80 ESI #3 19.6 0.4 106 2.32 (37.1) 4.9 10 7.5 50 ESI #3 49.1 0.9 1082.24 (35.8) 3.3 11 7.5 50 ESI #3 49.1 0.9 106 2.00 (32.0) 2.2 12 7.5 50ESI #3 49.1 0.9 105 1.92 (30.7) 4.3 13 7.5 50 ESI #3 49.1 0.9 104 1.95(31.2) 3.2 14 10 50 ESI #4 49.9 0.1 111 1.91 (30.6) 4.0 15 10 50 ESI #449.9 0.1 110 1.85 (29.6) 4.0 16 10 50 ESI #4 49.9 0.1 109 1.71 (27.4)3.7 17 10 50 ESI #4 49.9 0.1 108 1.75 (28.0) 3.8 ic4 in the isobutane inparts per hundred parts by weight of resin aPS is the atacticpolystyrene T_(f) is the foaming temperature in degree Centigrade pcf isthe density in pounds per cubic foot kg/m³ is the density in kilogramsper cubic meter % ESI interpolymer is the weight percent ESIinterpolymer based upon the total weight of ESI, aPS, and LDPE. % aPS isthe weight percent aPS based upon the total weight of ESI, aPS, and LDPEphr is the parts per hundred parts by weight of resin (polymer)

EXAMPLE 30

Closed cell LDPE/ESI resin blend foams were made in accordance with thepresent invention. A comparative example of a conventional, closed cellLDPE foam (Sample #1) was also made.

The present foams were made with the apparatus and techniques describedin Example 29.

The present foams were closed cell and exhibited smaller cell size,better skin quality, better toughness, better drape/conformability, andbetter softness compared to the closed cell LDPE foam. Results are setforth in Table 17.

TABLE 17 Open Type Cell of % ESI Density Con Cell Sample ic4 Percent ESIinter- % T_(f) pcf tent Size # (phr) LDPE Resin polymer aPS (° C.)(kg/m³) (%) (mm)  1* 7.5 100 0 0 112 2.35 (37.6) 4.5 1.63 2 7.5 50 ESI#3 49.1 0.9 105 1.92 (30.7) 4.3 0.90 3 7.5 80 ESI #2 19.8 0.2 106 2.37(37.9) 4.8 1.16 4 7.5 80 ESI #1 17.2 2.8 110 2.26 (36.2) 4.7 1.08 5 7.580 ESI #3 19.6 0.4 108 2.26 (36.2) 2.9 1.16 6 7.5 50 ESI #2 49.6 0.4 1062.38 (38.1) 7.0 1.16 7 10 50 ESI #4 49.9 0.1 109 1.71 (27.4) 3.7 1.02ic4 is the isobutane in parts per hundred parts by weight of resin aPSis the atactic polystyrene T_(f) is the foaming temperature in degreesCentigrade pcf is the density in pounds per cubic foot kg/m³ is thedensity in kilograms per cubic meter % ESI interpolymer is the weightpercent ESI interpolymer based upon the total weight of ESI, aPS andLDPE. aPS is the weight percent aPS based upon the total weight of ESI,aPS, and LDPE phr is the parts per hundred parts by weight of resin(polymer) * not an example of the present invention

EXAMPLE 31

Closed cell LDPE/ESI resin blend foams which exhibited excellentdimensional stability without the use of permeability modifiers weremade in accordance with the present invention. A comparative example ofa conventional, closed cell LDPE was also made without the use ofpermeability modifiers.

The present foams and the foam of the comparative example were made withthe apparatus and technique described in Example 29. Two different ESIresins were employed.

The foams made with LDPE/ESI resin blends and the foam of thecomparative example were kept at ambient temperature and measured forvolume change over time. The minimum or maximum volume, whicheverexhibited the most deviation, was noted. Volume change was measured bywater displacement. A maximum dimensional change of not more than 15percent (compared to the initial volume measured 60 seconds afterextrusion) was considered desirable.

The foams made with LDPE/ESI Resin #3 exhibited superior dimensionalstability compared to the LDPE foam of the comparative example and thefoams made with LDPE/ESI Resin #2. Results are set forth in Table 18below.

Excellent dimensional stability may permit foams to be made with fastpermeating blowing agents such as carbon dioxide and isobutane withoutthe need to use permeability modifiers like glycerol monostearate. Theuse of fast permeating blowing agents without permeability modifiers mayafford faster curing times (i.e., to very low levels of residual blowingagents and/or replacement of blowing agent in cell gas with air from theenvironment).

TABLE 18 Type Open Maximum of % ESI Density Cell Volume ic4 % ESI inter-% T_(f) pcf Content Change Sample (phr) LDPE Resin polymer aPS (° C.)(kg/m³) (%) (%)  1* 7.5 100 0 0 112 2.35 (37.6) 4.5 −28.45 2 7.5 50 ESI#3 49.1 0.9 110 2.67 (42.7) 4.7 +3.9 3 7.5 50 ESI #3 49.1 0.9 108 2.24(35.8) 3.3 +4.3 4 7.5 50 ESI #3 49.1 0.9 106 2.00 (32.0) 2.2 +2.7 5 7.550 ESI #3 49.1 0.9 105 1.92 (30.7) 4.3 +4.3 6 7.5 50 ESI #3 49.1 0.9 1041.95 (31.2) 3.2 +3.4 7 7.5 50 ESI #2 49.6 0.4 106 2.38 (38.1) 7.0 −38.8%8 7.5 50 ESI #2 49.6 0.4 104 2.94 (47.00 6.1 −37.2% ic4 is the isobutanein parts per hundred parts by weight of resin aPS is the atacticpolystyrene T_(f) is the foaming temperature in degrees Centigrade pcfis the density in pounds per cubic foot kg/m³ is the density inkilograms per cubic meter % ESI interpolymer is the weight percent ESIinterpolymer based upon the total weight of ESI, aPS and LDPE. % aPS isthe weight percent aPS based upon the weight of ESI, aPS, and LDPE phris the parts per hundred parts by weight of resin (polymer) * not anexample of the present invention

What is claimed is:
 1. A fabricated article other than a film comprisinga blend of polymeric materials consisting of (A) from 1 to 99 weightpercent of one or more α-olefin/vinylidene monomer non-crosslinkedsubstantially random interpolymers, wherein the distribution of themonomers of said interpolymers can be described by the Bernoullistatistical model or by a first or second order Markovian statisticalmodel, and each having been made from monomer components comprising: (1)from 0.5 to 65 mole percent of either (a) at least one vinylidenearomatic monomer, or (b) at least one hindered aliphatic vinylidenemonomer, corresponding to the formula:

 wherein A¹ is a sterically bulky, aliphatic or cycloaliphaticsubstituent of up to 20 carbons, R¹ is selected from the group ofradicals consisting of hydrogen and alkyl radicals containing from 1 to4 carbon atoms, preferably hydrogen or methyl; each R² is independentlyselected from the group of radicals consisting of hydrogen and alkylradicals containing from 1 to 4 carbon atoms, preferably hydrogen ormethyl; or alternatively R¹ and A¹ together form a ring system or (c) acombination of at least one vinylidene aromatic monomer and at least onehindered aliphatic vinylidene monomer; and (2) from 35 to 99.5 molepercent of at least one aliphatic α-olefin having from 2 to 20 carbonatoms; and (B) from 99 to 1 weight percent of one or more homopolymersor copolymers of monomer components comprising aliphatic α-olefinshaving from 2 to 20 carbon atoms, or aliphatic α-olefins having from 2to 20 carbon atoms and containing polar groups.
 2. A fabricated articleof claim 1 wherein (i) said blend comprises from 5 to 95 weight percentof component (A) and from 95 to 5 percent by weight of component (B);(ii) component (A) contains from 1 to 55 mole percent of component (A-1)residues and from 45 to 99 mole percent of component (A-2) residues; and(iii) component (B) comprises a homopolymer or copolymer of monomercomponents comprising two or more α-olefins having from 2 to 12 carbonatoms.
 3. A fabricated article of claim 1 wherein (i) said blendcomprises from 10 to 90 weight percent of component (A) and from 90 to10 percent by weight of component (B); and (ii) component (A) containsfrom 2 to 50 mole percent of component (A-1) residues and from 98 to 50mole percent of component (A-2) residues.
 4. A fabricated article ofclaim 1 wherein (i) component (A) is a substantially random interpolymerof styrene and ethylene or a combination of styrene and ethylene and atleast one C₃₋₈ α-olefin; and (ii) component (B) is a homopolymer ofethylene or propylene; or a copolymer of ethylene or propylene and atleast one other α-olefin containing from 4 to 8 carbon atoms; or acopolymer of ethylene or propylene and at least one of acrylic acid,vinyl acetate, maleic anhydride or acrylonitrile; or a terpolymer madefrom ethylene, propylene and a diene.
 5. A fabricated article of claim 2wherein (i) component (A) is a substantially random interpolymer ofstyrene and ethylene, or styrene, ethylene and at least one otherα-olefin containing from 3 to 8 carbon atoms; (ii) component (B) is ahomopolymer of ethylene or propylene, or a copolymer of ethylene and/orpropylene and at least one other α-olefin containing from 4 to 8 carbonatoms; or a terpolymer of ethylene, propylene and at least one of4-methyl pentene, butene-1, hexene-1 or octene-1.
 6. A fabricatedarticle of claim 3 wherein (i) component (A) is a substantially randominterpolymer of styrene and ethylene, or styrene and a combination ofethylene and at least one of propylene, 4-methyl pentene, butene-1,hexene-1, octene-1 or norbornene; (ii) component (B) is a homopolymer ofethylene or propylene; or a copolymer of ethylene or propylene and atleast one other α-olefin containing from 4 to 8 carbon atoms; or aterpolymer of ethylene, propylene and a diene.
 7. A fabricated articleof claim 1 wherein (1) component (A) is a substantially randominterpolymer of styrene and ethylene or styrene and a combination ofethylene and at least one of propylene, 4-methyl pentene, butene-1,hexene-1, octene-1 or norbornene; (2) component (B) is a homopolymer ofethylene or a combination of ethylene and at least one of propylene,4-methyl pentene, butene-1, hexene-1 or octene-1.
 8. A fabricatedarticle of claim 1 wherein (i) component (A) is a substantially randominterpolymer of styrene and ethylene; and (ii) component (B) is selectedfrom: (1) one or more homopolymers of ethylene, (2) one or morehomopolymers of propylene, (3) one or mores chlorinated polyethylenes,(4) one or more copolymers of ethylene and propylene, (5) one or morecopolymers of ethylene, propylene and a diene, (6) one or morecopolymers of ethylene and octene-1, (7) one or more copolymers ofethylene, propylene and norbornene, (8) one or more copolymers ofethylene and acrylic acid, (9) one or more copolymers of ethylene andvinyl acetate, or (10) any combination of any two or more of polymers(1)-(9).
 9. A fabricated article of claim 1 wherein (1) component (A) isa substantially random interpolymer made from 1-10 mole percent styreneand 90-99 mole percent ethylene or a combination of ethylene and atleast one of propylene, 4-methyl pentene, butene-1, hexene-1, octene-1or norbornene; and (2) component (B) is selected from: (1) one or morehomopolymers of ethylene, (2) one or more homopolymers of propylene, (3)one or mores chlorinated polyethylenes, (4) one or- more copolymers ofethylene and propylene, (5) one or more copolymers of ethylene,propylene and a diene, (6) one or more copolymers of ethylene andoctene-1, (7) one or more copolymers of ethylene, propylene andnorbornene, (8) one or more copolymers of ethylene and acrylic acid, (9)one or more copolymers of ethylene and vinyl acetate, or (10) anycombination of any two or more of polymers (1)-(9).
 10. A fabricatedarticle of claim 1 wherein (1) component (A) is a substantially randominterpolymer made from 10-25 mole percent styrene and 75 to 90 molepercent of ethylene or a combination of ethylene and at least one ofpropylene, 4-methyl pentene, butene-1, hexene-1, octene-1 or norbornene;and (2) component (B) is selected from: (1) one or more homopolymers ofethylene, (2) one or more homopolymers of propylene, (3) one or moreschlorinated polyethylenes, (4) one or more copolymers of ethylene andpropylene, (5) one or more copolymers of ethylene, propylene and adiene, (6) one or more copolymers of ethylene and octene-1, (7) one ormore copolymers of ethylene, propylene and norbornene, (8) one or morecopolymers of ethylene and acrylic acid, (9) one or more copolymers ofethylene and vinyl acetate, or (10) any combination of any two or moreof polymers (1)-(9).
 11. A fabricated article of claim 1 wherein (1)component (A) is a substantially random interpolymer made from 25-50mole percent styrene and 50 to 75 mole percent of ethylene or acombination of ethylene and at least one of propylene, 4-methyl pentene,butene-1, hexene-1, octene-1 or norbornene; and (2) component (B) isselected from: (1) one or more homopolymers of ethylene, (2) one or morehomopolymers of propylene, (3) one or mores chlorinated polyethylenes,(4) one or more copolymers of ethylene and propylene, (5) one or morecopolymers of ethylene, propylene and a diene, (6) one or morecopolymers of ethylene and octene-1, (7) one or more copolymers ofethylene, propylene and norbornene, (8) one or more copolymers ofethylene and acrylic acid, (9) one or more copolymers of ethylene andvinyl acetate, or (10) any combination of any two or more of polymers(1)-(9).
 12. A fabricated article of claim 1 consisting of (A) from 25to 99 weight percent of a substantially random interpolymer made frommonomer components comprising 1-10 mole percent styrene and 90 - 99 molepercent ethylene or a combination of ethylene and at least one ofpropylene, 4-methyl pentene, butene-1, hexene-1, octene-1 or norbornene;and (B) from 1 to 75 weight percent of a polymer component selectedfrom: (1) one or more homopolymers of ethylene, (2) one or morehomopolymers of propylene, (3) one or mores chlorinated polyethylenes,(4) one or more copolymers of ethylene and propylene, (5) one or morecopolymers of ethylene, propylene and a diene, (6) one or morecopolymers of ethylene and octene-1, (7) one or more copolymers ofethylene, propylene and norbornene, (8) one or more copolymers ofethylene and acrylic acid, (9) one or more copolymers of ethylene andvinyl acetate, or (10) any combination of any two or more of polymers(1)-(9).
 13. A fabricated article of claim 1 consisting of (A) from 1 to50 weight percent of an interpolymer made from monomer, componentscomprising 1-10 mole percent styrene and 90-99 mole percent ethylene ora combination of ethylene and at least one of propylene, 4-methylpentene, butene-1, hexene-1, octene-1 or norbornene; and (B) from 50 to99 weight percent of a polymer component selected from: (1) one or morehomopolymers of ethylene, (2) one or more homopolymers of propylene, (3)one or mores chlorinated polyethylenes, (4) one or more copolymers ofethylene and propylene, (5) one or more copolymers of ethylene,propylene and a diene, (6) one or more copolymers of ethylene andoctene-1, (7) one or more copolymers of ethylene, propylene and isnorbornene, (8) one or more copolymers of ethylene and acrylic acid, (9)one or more copolymers of ethylene and vinyl acetate, or (10) anycombination of any two or more of polymers (1)-(9).
 14. A fabricatedarticle of claim 1 consisting of (A) from 50 to 99 weight percent of aninterpolymer made from monomer components comprising 1-10 mole percentstyrene and 90-99 mole percent ethylene or a combination of ethylene andat least one of propylene, 4-methyl pentene, butene-1, hexene-1,octene-1 or norbornene; and (B) from 1 to 50 weight percent of a polymercomponent selected a from: (1) one or more homopolymers of ethylene, (2)one or more homopolymers of propylene, (3) one or mores chlorinatedpolyethylenes, (4) one or more copolymers of ethylene and propylene, (5)one or more copolymers of ethylene, propylene and a diene, (6) one ormore copolymers of ethylene and octene-1, (7) one or more copolymers ofethylene, propylene and norbornene, (8) one or more copolymers ofethylene and acrylic acid, (9) one or more copolymers of ethylene andvinyl acetate, or (10) any combination of any two or more of polymers(1)-(9).
 15. A fabricated article of claim 1 consisting of (A) from 25to 99 weight percent of an interpolymer made from monomer componentscomprising 10-25 mole percent styrene and 75 to 90 mole percent ofethylene or a combination of ethylene and at least one of propylene,4-methyl pentene, butene-1, hexene-1, octene-1 or norbornene; and (B)from 1 to 75 weight percent of a polymer component selected from: (1)one or more homopolymers of ethylene, (2) one or more homopolymers ofpropylene, (3) one or mores chlorinated polyethylenes, (4) one or morecopolymers of ethylene and propylene, (5) one or more copolymers ofethylene, propylene and a diene, (6) one or more copolymers of ethyleneand octene-1, (7) one or more copolymers of ethylene, propylene andnorbornene, (8) one or more copolymers of ethylene and acrylic acid, (9)one or more copolymers of ethylene and vinyl acetate, or (10) anycombination of any two or more of polymers (1)-(9).
 16. A fabricatedarticle of claim 1 wherein each of components (A) and (B) are producedby polymerization or copolymerization of the appropriate monomers in thepresence of a metallocene catalyst and a co-catalyst.
 17. A fabricatedarticle of any of claims 1-16 in the form of an injection, compression,extruded or blow molded part.